Render API docs in PR previews

[jameslamb]

Description

PR previews like this:

#679 (comment)

Don't currently add in all the API docs. That makes it difficult to test changes to https://docs.rapids.ai/api/

The API docs should be rendered in PR previews, or the process to test them should be made easier in some other way.

Benefits of this work

• improves release confidence in changes related to the API docs
• reduces the total maintenance and reviewer effort needed to make changes to the API docs

Acceptance Criteria

• API docs are rendered in PR previews, or some other method exists that makes it easier for contributors and reviewers to preview those docs

Approach

See the following:

• how the site is built on merge: https://github.com/rapidsai/docs/blob/main/.github/workflows/deploy.yaml
• PR that added docs on how to do this locally: expand docs on testing locally #659
• those docs: https://github.com/rapidsai/docs/blob/main/CONTRIBUTING.md#local-macos-development

Notes

N/A