Make it easy to contribute to the docs by carving out the docs

🚀 Feature

Separate docs repository that is easy and lightning fast to contribute to. 😄

Motivation

When something is hard only a small subset of people want to contribute. Contributing to the docs could be very easy and lightning fast. But its not, because the docs are part of a large repository with a very heavy installation and build process.

Context

I just want to contribute examples to the documentation about adding web ui to the Lightning Framework. I'm working on windows in a constrained enterprise environment. I cannot install make. I can install python packages via pip and conda. I can use docker.

cc @borda @rohitgr7