This PR revamps and aligns the README and Ray intro doc page:
New "What is Ray" diagram that introduces AIR vs Ray core (diagram TBD finalized, this is the working placeholder)
Update the description of Ray
Link out to the user guides for key libraries and key concepts
Remove old / broken links, as well as the inline library descriptions from the README
Pointing to the latest documentation for contributor is important as the workflow is always evolving. E.g. the installation instructions for bazel are not representatives of the current state on release vs master. Hence, I propose to update contribution links in the documentation to point to the latest state on master.
the include of content for md files like our central getting started page didn't render. fixed here.
Signed-off-by: Max Pumperla <max.pumperla@googlemail.com>
Preview: [docs](https://ray--21931.org.readthedocs.build/en/21931/data/dataset.html)
The Ray Data project's docs now have a clearer structure and have partly been rewritten/modified. In particular we have
- [x] A Getting Started Guide
- [x] An explicit User / How-To Guide
- [x] A dedicated Key Concepts page
- [x] A consistent naming convention in `Ray Data` whenever is is referred to the project.
This surfaces quite clearly that, apart from the "Getting Started" sections, we really only have one real example. Once we have more, we can create an "Example" section like many other sub-projects have. This will be addressed in https://github.com/ray-project/ray/issues/21838.
