Support literal square brackets in format strings

[knowledgecode]

Summary

• Support escaping square brackets with backslashes to output them literally in formatted dates
• Update documentation with examples demonstrating the new escape feature
• Migrate ESLint configuration from TypeScript to JavaScript

Changes

Core Functionality

• Modified compile() function to handle escaped square brackets (\[ and \])
• Added support for literal bracket output in format() and parsing in parse()

Documentation

• Added escape examples to compile.md, format.md, and parse.md
• Updated Logger example in compile.md to demonstrate the new feature
• Fixed plugin system description in index.md

Development

• Migrated eslint.config.ts to eslint.config.js
• Updated dependencies to latest versions

Test plan

• Added test cases for escaped brackets in compile.spec.ts
• Added test cases for escaped brackets in parse.spec.ts
• All existing tests pass
• Documentation examples verified