Add initial project structure and core functionality for ArchDoc

- Created `.gitignore` files for various directories to exclude unnecessary files.
- Added `PLAN.md` to outline the project goals and architecture documentation generation.
- Implemented the `archdoc-cli` with a command-line interface for initializing and generating documentation.
- Developed the `archdoc-core` library for analyzing Python projects and generating architecture documentation.
- Included caching mechanisms to optimize repeated analysis.
- Established a comprehensive test suite to ensure functionality and error handling.
- Updated `README.md` to provide an overview and installation instructions for ArchDoc.

test-project/src/utils.py

@@ -0,0 +1,26 @@
+"""Utility functions for the test project."""
+
+import json
+import os
+
+def load_config(config_path: str) -> dict:
+    """Load configuration from a JSON file."""
+    with open(config_path, 'r') as f:
+        return json.load(f)
+
+def save_config(config: dict, config_path: str):
+    """Save configuration to a JSON file."""
+    with open(config_path, 'w') as f:
+        json.dump(config, f, indent=2)
+
+def get_file_size(filepath: str) -> int:
+    """Get the size of a file in bytes."""
+    return os.path.getsize(filepath)
+
+def format_bytes(size: int) -> str:
+    """Format bytes into a human-readable string."""
+    for unit in ['B', 'KB', 'MB', 'GB']:
+        if size < 1024.0:
+            return f"{size:.1f} {unit}"
+        size /= 1024.0
+    return f"{size:.1f} TB"