Enhance documentation with SEO metadata and layout

Added a new custom layout template for SEO and social media meta tags. Updated multiple documentation files with metadata for improved search engine optimization and social sharing. Enhanced Sphinx configuration with additional HTML options and meta tags.

docs/api/cli.md

@@ -1,3 +1,13 @@
+---
+html_meta:
+  description: "tzst CLI API - Command-line interface functions and utilities for tar.zst archive operations"
+  keywords: "tzst CLI API, command line interface, Python CLI, tar.zst commands"
+  og:title: "tzst CLI API Reference"
+  og:description: "CLI API documentation for tzst - Command-line interface functions and utilities"
+  twitter:title: "tzst CLI API Reference"
+  twitter:description: "CLI API documentation for tzst - Command-line interface functions and utilities"
+---
+
 # CLI API
 
 The command-line interface module provides comprehensive functionality for the tzst CLI tool, including argument parsing, command execution, and interactive features.

docs/api/core.md

@@ -1,3 +1,13 @@
+---
+html_meta:
+  description: "tzst Core API - TzstArchive class and convenience functions for tar.zst archive operations"
+  keywords: "tzst core API, TzstArchive, Python archive class, tar.zst functions"
+  og:title: "tzst Core API Reference"
+  og:description: "Core API documentation for tzst - TzstArchive class and convenience functions"
+  twitter:title: "tzst Core API Reference"
+  twitter:description: "Core API documentation for tzst - TzstArchive class and convenience functions"
+---
+
 # Core API
 
 The core module provides the main functionality for working with tzst archives, including the primary `TzstArchive` class and high-level convenience functions.

docs/api/exceptions.md

@@ -1,3 +1,16 @@
+---
+html_meta:
+  description: "Complete reference for tzst exception classes and error handling. Learn about TzstError, TzstArchiveError, and other custom exceptions for robust archive operations."
+  keywords: "tzst exceptions, Python exceptions, error handling, TzstError, TzstArchiveError, archive errors, compression errors"
+  "og:title": "tzst Exceptions API Reference"
+  "og:description": "Complete reference for tzst exception classes and error handling. Learn about TzstError, TzstArchiveError, and other custom exceptions for robust archive operations."
+  "og:type": "article"
+  "twitter:title": "tzst Exceptions API Reference"
+  "twitter:description": "Complete reference for tzst exception classes and error handling. Learn about TzstError, TzstArchiveError, and other custom exceptions for robust archive operations."
+  "article:section": "API Reference"
+  "article:tag": "exceptions, error handling, API"
+---
+
 # Exceptions API
 
 Custom exception classes used by tzst for comprehensive error handling and debugging.

docs/api/index.md

@@ -1,3 +1,13 @@
+---
+html_meta:
+  description: "Complete tzst API reference - Core functions, CLI tools, and exception handling for tar.zst archives"
+  keywords: "tzst API, Python API documentation, tar.zst API reference, archive API"
+  og:title: "tzst API Reference"
+  og:description: "Complete API reference for tzst - Core functions, CLI tools, and exception handling"
+  twitter:title: "tzst API Reference"
+  twitter:description: "Complete API reference for tzst - Core functions, CLI tools, and exception handling"
+---
+
 # API Reference
 
 This section contains the complete API documentation for tzst, providing detailed information about classes, functions, and exceptions.