[DOC] Create Initial Documentation

[RNKuhns]

Describe the documentation issue

Create an initial documentation for the package.

Suggest a concrete fix/improvement

There is currently no documentation. We should create basic documentation ahead of the first release. The docs can be improved in the subsequent releases.

There should be a landing (index) page, a get started page, API Reference, basic developer documentation, and a changelog. Additional user documentation can be added later, along with full developer documentation.