Feat: Auto patcher to aid in developemnt workflow and some docs changes

[RunTheBot]

This pull request introduces a new plugin system for the Deezer desktop app, including a robust setup script, platform-aware plugin directory management, and improved documentation. The main changes are the addition of a setup.js installer script, a cross-platform paths.js utility, a comprehensive plugin_loader.js, and updates to the documentation to guide users through the new process.

Plugin System Implementation

• Added src/plugin_loader.js to handle dynamic loading and execution of plugins, with enhanced error handling and support for multiple plugin contexts (main, preload, renderer, titlebar).
• Added src/paths.js to provide platform-specific paths for plugin storage, ensuring compatibility across Windows, macOS, and Linux.

Installer and Setup Improvements

• Added src/setup.js, a setup script that automates extraction, patching, and repacking of Deezer's app.asar, supports debug mode, and ensures plugins are correctly integrated and directories are created.

Documentation Updates

• Updated docs/setup.md to include new instructions for placing plugin_loader.js and paths.js, clarifying their location and role in the setup process.
• Improved patch instructions in docs/setup.md to clarify context usage for plugin execution, specifically for the renderer and titlebar contexts.

[bertigert]

I was thinking about creating a setup script, will probably do that for the next update, however, I also need to rework the injection code, since it's overly complicated, so the patches will be outdated and besides, I also changed/added stuff other than the injection code. I'll leave this open so that I don't forget, but I won't merge it, since I don't like AI code and your provided scripts are all in the wrong path anyways.