Add documentation. (#321)

Add documentation that covers:

- Prediction
- Measuremnt
- REST API

Add Python scripts that support automatic documentation generation using the Sphinx
sphinxcontrib.eval extension.

Add automatic update/ test for REST API documentation.

Filter proxy endpoints from REST API documentation.

Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>

scripts/generate_openapi.py

@@ -0,0 +1,69 @@
+#!.venv/bin/python
+"""This module generates the OpenAPI specification for the FastAPI application  defined in `akkudoktoreos.server.fastapi_server`.
+
+The script can be executed directly to generate the OpenAPI specification
+either to the standard output or to a specified file.
+
+Usage:
+    scripts/generate_openapi.py [--output-file OUTPUT_FILE]
+
+Arguments:
+    --output-file : Optional. The file path to write the OpenAPI specification to.
+
+Example:
+    scripts/generate_openapi.py --output-file openapi.json
+"""
+
+import argparse
+import json
+import sys
+
+from fastapi.openapi.utils import get_openapi
+
+from akkudoktoreos.server.fastapi_server import app
+
+
+def generate_openapi() -> dict:
+    """Generate the OpenAPI specification.
+
+    Returns:
+        openapi_spec (dict): OpenAPI specification.
+    """
+    openapi_spec = get_openapi(
+        title=app.title,
+        version=app.version,
+        openapi_version=app.openapi_version,
+        description=app.description,
+        routes=app.routes,
+    )
+
+    return openapi_spec
+
+
+def main():
+    """Main function to run the generation of the OpenAPI specification."""
+    parser = argparse.ArgumentParser(description="Generate OpenAPI Specification")
+    parser.add_argument(
+        "--output-file", type=str, default=None, help="File to write the OpenAPI Specification to"
+    )
+
+    args = parser.parse_args()
+
+    try:
+        openapi_spec = generate_openapi()
+        openapi_spec_str = json.dumps(openapi_spec, indent=2)
+        if args.output_file:
+            # Write to file
+            with open(args.output_file, "w") as f:
+                f.write(openapi_spec_str)
+        else:
+            # Write to std output
+            print(openapi_spec_str)
+
+    except Exception as e:
+        print(f"Error during OpenAPI specification generation: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()