[FEA]: Make nemo_retriever python API docs

[randerzander]

Is this a new feature, an improvement, or a change to existing functionality?

New Feature

How would you describe the priority of this feature request

Significant improvement

Please provide a clear description of problem this feature solves

We need to build and publish API docs for the nemo_retriever library on GitHub pages

Describe the feature, and optionally a solution or implementation and any alternatives

make and publish python API docs

Additional context

No response