Adds basic yarn support

[Robert27]

🤖 Generated by Copilot at ba4195d

Summary

🛠️🚫📝

This pull request updates the Yarn settings, the win95.css dependency, and the README.md file of the rogue-thi-app subfolder. The changes aim to enhance the privacy, consistency, and documentation of the app.

yarnrc settings privacy and consistency autumn leaves falling

Walkthrough

• Disable Yarn telemetry and specify node-modules linker in .yarnrc.yml file (link)
• Ignore /.yarn folder in Git for rogue-thi-app subfolder (link)
• Use exact commit hash for win95.css dependency in package.json file for rogue-thi-app subfolder (link)
• Add dependency installation and node.js version error note to README.md file for rogue-thi-app subfolder (link)

Notes

• .yarnrc.yml is necessary to ensure support for newer Yarn versions (PnP does not work with sass)
• Win95 dependency has been adjusted to avoid Yarn errors due to wrong hash format (still works with npm)
• Yarn is only enabled as an alternative, but not as a replacement of NPM

[Robert27]

Is this PR stale? If you don't want yarn support, we should still update the docs regarding the node flag.