Enhance documentation for tzst library

- Updated the introduction to provide a clearer overview of tzst's capabilities and features.
- Expanded the Key Features section with detailed descriptions and icons for better readability.
- Improved the Quick Example section to include both command line and Python API usage.
- Added installation options with detailed steps for PyPI, standalone binaries, and source installation.
- Enhanced the Quick Start Guide with structured installation methods and basic usage examples.
- Introduced advanced features like security filters, conflict resolution, and performance optimization.
- Provided comprehensive error handling and common patterns for backup scripts and archive verification.
- Updated the requirements and reference links for better navigation.

docs/api/index.md

@@ -1,6 +1,6 @@
 # API Reference
 
-This section contains the complete API documentation for tzst.
+This section contains the complete API documentation for tzst, providing detailed information about classes, functions, and exceptions.
 
 ```{toctree}
 :maxdepth: 2
@@ -12,13 +12,22 @@ exceptions
 
 ## Overview
 
-The tzst library provides both high-level convenience functions and a comprehensive class-based API for working with `.tzst`/`.tar.zst` archives.
+The tzst library provides both high-level convenience functions and a comprehensive class-based API for working with `.tzst`/`.tar.zst` archives. The library is designed with security, performance, and ease of use in mind.
 
 ### Main Components
 
-- **{doc}`core`**: Core functionality including `TzstArchive` class and convenience functions
-- **{doc}`cli`**: Command-line interface functions and utilities  
-- **{doc}`exceptions`**: Custom exception classes for error handling
+- **{doc}`core`**: Core functionality including `TzstArchive` class and convenience functions for archive operations
+- **{doc}`cli`**: Command-line interface functions and utilities for batch operations
+- **{doc}`exceptions`**: Custom exception classes for comprehensive error handling and debugging
+
+### Architecture Overview
+
+The tzst library follows a layered architecture:
+
+1. **High-Level API**: Convenience functions for common operations
+2. **Class-Based API**: `TzstArchive` class for advanced control
+3. **CLI Interface**: Command-line tools for interactive and scripted use
+4. **Exception System**: Comprehensive error handling for robust applications
 
 ### Quick Reference
 
@@ -33,6 +42,8 @@ The tzst library provides both high-level convenience functions and a comprehens
    TzstArchive
 ```
 
+The main class for archive manipulation with context manager support and comprehensive functionality.
+
 #### Convenience Functions
 
 ```{eval-rst}
@@ -45,7 +56,26 @@ The tzst library provides both high-level convenience functions and a comprehens
    test_archive
 ```
 
-#### Exceptions
+High-level functions that provide simple interfaces for common archive operations.
+
+#### CLI Functions
+
+```{eval-rst}
+.. currentmodule:: tzst.cli
+
+.. autosummary::
+   :nosignatures:
+   
+   main
+   create_parser
+   print_banner
+   format_size
+   validate_compression_level
+```
+
+Command-line interface utilities for interactive and batch operations.
+
+#### Exception Classes
 
 ```{eval-rst}
 .. currentmodule:: tzst.exceptions
@@ -53,6 +83,37 @@ The tzst library provides both high-level convenience functions and a comprehens
 .. autosummary::
    :nosignatures:
    
+   TzstError
    TzstArchiveError
+   TzstCompressionError
    TzstDecompressionError
 ```
+
+Exception hierarchy for comprehensive error handling and debugging support.
+
+## Key Features
+
+### 🛡️ Security First
+
+- Built-in path traversal protection
+- Multiple security filter options
+- Safe extraction by default
+
+### ⚡ High Performance  
+
+- Zstandard compression with configurable levels
+- Streaming support for large archives
+- Memory-efficient operations
+
+### 🔧 Developer Friendly
+
+- Clean, Pythonic API
+- Comprehensive error handling
+- Context manager support
+- Extensive documentation and examples
+
+### 🌐 Cross-Platform
+
+- Works on Windows, macOS, and Linux
+- Consistent behavior across platforms
+- Native performance optimizations