Rivet Editor & Rivet Modules integrated deeply with the plugins, plus auto-generated SDKs

The Rivet Godot plugin v2.1.0 includes:

• Rivet Editor which allows for easy customizatin of Rivet Modules.
• A new Modules tab that lista all installed modules for easy access to documentation & customization.
• Drastically simplified the setup experience by removing the need to manually generate the Rivet SDK. It's now generated automatically when you change the Rivet config.