[Docs] /docs in repo should have a README.md that links to the docs

[rysweet]

What feature would you like to be added?

if browsing the repo there is a top level /docs dir that doesn't have much in it - we need at least a readme there that points to the preferred docs entry point.

Why is this needed?

should be super easy to find the docs

[jackgerrits]

The main entrypoint is here:

The plan is to repoint this to 0.4 once it is released