Render API docs in PR previews

Description

PR previews like this:

https://github.com/rapidsai/docs/pull/679#issuecomment-3292022542

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: #659
• those docs: https://github.com/rapidsai/docs/blob/main/CONTRIBUTING.md#local-macos-development

Notes

N/A

Start with .github/workflows/deploy.yaml to understand how the site is built on merge, then review PR #659 and the CONTRIBUTING.md local-macos-development section. Compare that process with the PR preview linked in the issue. Done means API docs are rendered in PR previews, or contributors and reviewers have an easier documented way to preview them.