[doc] Update changelog and readme files

[forfudan]

This pull request includes several updates and improvements to the README.md and other documentation files for the DeciMojo library, as well as the addition of a new changelog. The most important changes include the introduction of BigUInt, updates to the installation instructions, and enhancements to the BigInt and Decimal functionalities.

Enhancements to BigInt and BigUInt:

• Added a new BigUInt type and extended the BigInt type to support unlimited precision arithmetic, comprehensive arithmetic operations, and efficient handling of extremely large integers. [1] [2]
• Enhanced BigInt with floor division, truncate division, modulo, and power operations. [1] [2]

Updates to Installation Instructions:

• Updated the installation instructions to reflect the new version 0.2.0 in the mojoproject.toml file.

Documentation Improvements:

• Updated the README.md to reflect changes in the BigInt and Decimal types, including new mathematical functions and division operations. [1] [2]
• Added a new docs/changelog.md file to document the changes and improvements in version 0.2.0, including performance benchmarks and detailed descriptions of new features and bug fixes.

Additional Changes:

• Made minor updates to the Chinese documentation (docs/readme_zht.md) to include the new BigUInt type and updated installation instructions.

[Copilot]

Pull Request Overview

This pull request updates documentation files and the project manifest to reflect the new version (v0.2.0) and highlights the expanded arithmetic capabilities with the addition of the BigInt and BigUInt types. Key changes include:

• Updating version information in mojoproject.toml.
• Revising the README.md and docs/readme_zht.md files with expanded details on arithmetic operations, installation, and usage examples.
• Adding a new docs/changelog.md file with detailed release notes and performance benchmarks.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
mojoproject.toml	Updated version from v0.1.0 to v0.2.0
docs/readme_zht.md	Revised Chinese documentation text and updated details about arithmetic types
docs/changelog.md	New changelog document with release notes and benchmark comparisons
README.md	Updated installation instructions, examples for BigInt/BigUInt, and version

Comments suppressed due to low confidence (1)

README.md:228

• [nitpick] The documentation for the BigInt implementation changed from describing a base-10^9 internal representation to a base-10 one; please clarify which representation is actually used to avoid potential confusion.

[^integer]: The BigInt implementation uses a base-10 representation for efficient storage and calculations, supporting operations on integers with unlimited precision. It provides both floor division (round toward negative infinity) and truncate division (round toward zero) semantics, enabling precise handling of division operations with correct mathematical behavior regardless of operand signs.

[Copilot]

Pull Request Overview

This PR updates documentation and configuration to reflect the v0.2.0 release of DeciMojo, including new BigInt and BigUInt types and enhanced arithmetic functionality. Key changes include:

• Updating the version number in mojoproject.toml to v0.2.0.
• Revising both English and Chinese documentation to include updated installation instructions, API examples, and new features.
• Adding a comprehensive changelog that details performance improvements, new arithmetic operations, and additional enhancements.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
mojoproject.toml	Updated dependency version to v0.2.0.
docs/readme_zht.md	Updated documentation with new features, improved installation instructions, and revised API examples.
docs/changelog.md	Added changelog entries for v0.2.0 detailing new functionality, performance benchmarks, and bug fixes.
README.md	Updated dependency version, consolidated module imports, and revised API examples for new BigInt and BigUInt operations.

Comments suppressed due to low confidence (2)

README.md:154

• Please confirm that updating BigInt's internal representation to 'base-10' (from a previous base-10^9 description) is intentional and that all related documentation and code reflect this change consistently.

Although the name emphasizes decimals with fractional parts, DeciMojo embraces the full spectrum of decimal mathematics. Our `BigInt` type, while handling only integers, is designed specifically for the decimal numeral system with its base-10 internal representation.

README.md:103

• [nitpick] Ensure the updated module import path for BigInt is correct and consistently documented across all examples.

from decimojo import BigInt

[Copilot]

Pull Request Overview

This pull request updates documentation files and the configuration to document and support the new v0.2.0 release of DeciMojo, with major additions including the new BigUInt type and enhanced arithmetic operations for Decimal and BigInt.

• Update version in mojoproject.toml to "0.2.0"
• Revise README.md and Chinese documentation with updated links, installation instructions, and usage examples including the new BigUInt additions
• Add a comprehensive changelog with performance benchmarks and detailed release notes

Reviewed Changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated no comments.

File	Description
mojoproject.toml	Updated the version to "0.2.0".
docs/readme_zht.md	Revised Chinese documentation, updated description text and formatting.
docs/changelog.md	Added a new changelog documenting the changes in v0.2.0.
README.md	Updated links, dependency version, examples and added BigInt alias usage.

Files not reviewed (2)

• src/decimojo/init.mojo: Language not supported
• src/decimojo/bigint/bigint.mojo: Language not supported

Comments suppressed due to low confidence (1)

README.md:155

• The documentation now states that BigInt uses a base-10 internal representation, which conflicts with earlier references (e.g. in the Chinese documentation) that mention a base-10^9 representation. Please update the documentation to use a consistent internal representation for clarity.

Although the name emphasizes decimals with fractional parts, DeciMojo embraces the full spectrum of decimal mathematics. Our `BigInt` type, while handling only integers, is designed specifically for the decimal numeral system with its base-10 internal representation. This approach offers optimal performance while maintaining human-readable decimal semantics, contrasting with binary-focused libraries. Furthermore, `BigInt` serves as the foundation for our `BigDecimal` implementation, enabling arbitrary-precision calculations across both integer and fractional domains.

[Copilot]

Pull Request Overview

This PR provides documentation updates and improvements for the DeciMojo library in preparation for the v0.2.0 release. Key changes include:

• Bumping the package version to 0.2.0 in the mojoproject.toml file.
• Updating the Chinese and English documentation (README.md, docs/readme_zht.md) to reflect new features such as BigUInt and enhanced BigInt operations.
• Adding a new changelog (docs/changelog.md) that details performance improvements, architectural changes, and expanded functionality.

Reviewed Changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated no comments.

File	Description
mojoproject.toml	Updated version from 0.1.0 to 0.2.0 to reflect the current release.
docs/readme_zht.md	Revised Chinese documentation with expanded details on BigInt/BigUInt and updated installation instructions, with minor content reordering/adjustments.
docs/changelog.md	Added new changelog documenting the v0.2.0 release notes, performance benchmarks, and new features.
README.md	Updated dependency version, adjusted hyperlinks, and introduced the BInt alias for BigInt along with minor textual clarifications.

Files not reviewed (2)

• src/decimojo/init.mojo: Language not supported
• src/decimojo/bigint/bigint.mojo: Language not supported

Comments suppressed due to low confidence (3)

README.md:155

• Please confirm that the change from a previously mentioned base‑10^9 internal representation to a base‑10 representation accurately reflects the implementation of BigInt.

Although the name emphasizes decimals with fractional parts, DeciMojo embraces the full spectrum of decimal mathematics. Our `BigInt` type, while handling only integers, is designed specifically for the decimal numeral system with its base-10 internal representation.

README.md:103

• [nitpick] Consider adding a brief inline comment or documentation note to explain the purpose of the 'BInt' alias for BigInt for clarity.

from decimojo import BigInt, BInt

docs/readme_zht.md:150

• [nitpick] Consider removing or replacing the classical scripture quote from this section to maintain a consistent technical tone in the documentation.

> 得此魔咒者，即脱凡相，識天數，斬三尸，二十七日飛升。

[Copilot]

Pull Request Overview

This PR updates the documentation for DeciMojo to reflect the new v0.2.0 release, including updated installation instructions, expanded details for the newly introduced BigUInt type, and comprehensive changelog entries. The key changes include:

• Updating the version number to "0.2.0" in mojoproject.toml.
• Enhancements to the Chinese documentation (docs/readme_zht.md) and README.md with revised examples, improved links, and clearer descriptions of BigInt/BigUInt.
• Introducing a changelog (docs/changelog.md) that details performance improvements and new features.

Reviewed Changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated no comments.

File	Description
mojoproject.toml	Version bump from 0.1.0 to 0.2.0 to reflect the new release.
docs/readme_zht.md	Updated Chinese documentation to mention the new BigUInt support and revised installation instructions.
docs/changelog.md	New file added to document the comprehensive changes and performance improvements in v0.2.0.
README.md	Updated links, installation instructions, and code examples to refer to the new version and alias BInt.

Files not reviewed (2)

• src/decimojo/init.mojo: Language not supported
• src/decimojo/bigint/bigint.mojo: Language not supported

Comments suppressed due to low confidence (1)

README.md:103

• [nitpick] The alias 'BInt' is brief and may be unclear to users; consider using a more descriptive alias or adding a clarifying comment to ensure consistency in user code.

from decimojo import BigInt, BInt