Add comprehensive documentation and code comments

This commit adds extensive documentation to the Mistral OCR CLI project:

- Add API.md with detailed API response format documentation
- Add CHANGELOG.md to track version changes
- Add CONTRIBUTING.md with guidelines for contributors
- Enhance README.md with more detailed usage examples and troubleshooting
- Add proper docstrings to all Python modules and functions
- Update requirements.txt with development dependencies
- Improve setup.py with better metadata

These changes make the project more accessible to users and contributors.

mistral_ocr/commands/process.py

@@ -6,6 +6,14 @@ import urllib.parse
 from mistral_ocr.client import MistralClient
 
 def run(args):
+    """
+    Main entry point for the process command.
+    
+    Processes a document with OCR, either from a URL or a local file.
+    
+    Args:
+        args: Command line arguments parsed by argparse
+    """
     file_path = args.file
     
     # Determine if input is a URL or a local file
@@ -15,6 +23,17 @@ def run(args):
         process_local_file(file_path, args.output_file, args.include_images)
 
 def process_url(url, output_file, include_image_base64):
+    """
+    Process a document from a URL.
+    
+    Args:
+        url (str): URL of the document to process
+        output_file (str): Path to save the OCR results, or None for stdout
+        include_image_base64 (bool): Whether to include base64-encoded images in the output
+        
+    Raises:
+        SystemExit: If an error occurs during processing
+    """
     try:
         client = MistralClient()
         
@@ -35,6 +54,17 @@ def process_url(url, output_file, include_image_base64):
         sys.exit(1)
 
 def process_local_file(file_path, output_file, include_image_base64):
+    """
+    Process a local document file.
+    
+    Args:
+        file_path (str): Path to the local file to process
+        output_file (str): Path to save the OCR results, or None for stdout
+        include_image_base64 (bool): Whether to include base64-encoded images in the output
+        
+    Raises:
+        SystemExit: If an error occurs during processing
+    """
     try:
         print(f"Processing local file: {file_path}")
         
@@ -71,6 +101,13 @@ def process_local_file(file_path, output_file, include_image_base64):
         sys.exit(1)
 
 def handle_output(data, output_file):
+    """
+    Handle the OCR response output.
+    
+    Args:
+        data (bytes): JSON response data from the OCR API
+        output_file (str): Path to save the OCR results, or None for stdout
+    """
     # Pretty print the JSON response
     pretty_json = json.dumps(json.loads(data), indent=2)