Add gcp_client and events docs to gh-pages deployment

[aaraney]

These subpackages need to be added to the sphinx docs so they are deployed on gh-pages.

[jarq6c]

@aaraney Can you document a minimal guide or step-by-step instructions to add new subpackages to the sphinx docs?

[aaraney]

Working on that now. I think it makes sense to turn this into a GH action so that they are auto deployed, so I will likely just cover how to add new documentation.