v0.2.2

Add authentication support to singlerpc proxy

- Introduced an authentication token feature requiring clients to provide a token via headers or query parameters.
- Updated README.md to document the new `-a, --auth <TOKEN>` option.
- Modified main.rs to include the new auth_token argument in the CLI.
- Enhanced proxy.rs to validate the provided token and respond with unauthorized status if missing or invalid.
- Added unit tests for token extraction from headers and query parameters.