Replace CRA with Vite

[entriphy]

Motivation:

• Commit 163c6b9 causes npm install to fail, as react-scripts requires TypeScript v4, but the project now uses TypeScript v5.
• Create React App/react-scripts has been abandoned, and Vite is widely considered to be its modern replacement.

Main changes:

• Add Vite and remove react-scripts from dependencies
• Replace all scripts that use Create React App with its Vite equivalent in package.json
• Update other React and MUI dependencies, which fixes some issues when building for production with styled MUI components
• Move index.html to the root directory (required by Vite)
• The base URL for the React router is now controlled by the BASE_URL environment variable
  • The user can either set this environment variable or manually change it in vite.config.ts. Otherwise, it defaults to /.
  • i.e. if the user is deploying to deploying to [username].github.com/Website, the user can run BASE_URL=/Website npm run build. The pathSegmentsToKeep variable in public/404.html still has to be changed in this case.

Preview: https://entriphy.github.io/Website