Add comprehensive Portuguese project overview (README.md)

[Copilot]

Adds a comprehensive project overview in Portuguese as requested in issue. The README.md provides detailed documentation about the Artcode programming language project, including:

Overview

Artcode is a simple, modern programming language implemented in Rust that demonstrates a complete language implementation from lexical analysis to interpretation.

Key Documentation Added

• Project structure: Detailed explanation of the modular Rust workspace architecture
• Language features: Currently implemented functionality vs. planned features
• Installation and usage: Step-by-step build and execution instructions
• Syntax examples: Working code samples for all implemented features
• CLI usage: Both file execution and REPL mode documentation
• Development status: Clear categorization of implemented, in-development, and planned features

Language Features Documented

Currently Working:

• Basic data types (integers, floats, strings, booleans)
• Variables with let declarations
• Mathematical and logical operations
• Control flow with if/else
• Variable scoping with blocks
• Interactive REPL mode

In Development:

• Custom structs and enums
• Pattern matching with match
• Function definitions
• Arrays and collections

Technical Implementation

The documentation accurately reflects the current state of the language implementation, with all examples tested and verified to work correctly. Advanced features like structs, enums, and pattern matching are clearly marked as "in development" since they currently have parsing issues.

This provides Portuguese-speaking users with a complete understanding of the project's capabilities, architecture, and usage patterns.

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