cleanup repository

[xalechez]

This PR removes a lot of unnecessary stuff remaining from the upstream repository:

• All code generators and templates (they are the same as upstream, we won't own them at any point of time)
• All e2e tests (they only thing they test is that Facebook origin works well)
• docusaurus-website (we don't want to compete with https://create-react-app.dev)
• A lot of other tools that are dependencies of the above or the ones we don't use in this fork

What has left:

• All direct dependencies of react-scripts package

As a result we mitigate a lot of security issues coming from the removed packages