Readme and mkShell missing in docs

**Describe the bug** <!-- A clear and concise description of what the bug is. --> I was searching for docs on `mkShell` in the docs page, but there's no mention to it. And it's so basic! There are some small mentions to it in the repo readme, but turns out that readme is not rendered in the online docs. **Expected behavior** <!-- A clear and concise description of what you expected to happen. --> Readme contents should be found also in docs. `mkShell` should be documented in docs.