[docs] [ci] update website, move docs files out of source control

[jameslamb]

Testing moving docs deployments to this pattern:

https://docs.github.com/en/pages/getting-started-with-github-pages/configuring-a-publishing-source-for-your-github-pages-site#publishing-with-a-custom-github-actions-workflow

Benefits:

• no need to check all these HTML/CSS/JS files into source control
• automatically keeps the docs up to date with the current state of the code (no need to manually re-generate it)

Notes for Reviewers

Replaces #241.

[jameslamb]

Now CI has more than just tests.

Also this shorter prefix makes it a little easier to read in the UI:

[jameslamb]

Suggested change

	#deploy: ${{ (github.event_name == 'push' && startsWith(github.ref, 'refs/tags')) || (github.event_name == 'workflow_dispatch' && inputs.deploy-docs == true) }}
	deploy: true
	deploy: ${{ (github.event_name == 'push' && startsWith(github.ref, 'refs/tags')) || (github.event_name == 'workflow_dispatch' && inputs.deploy-docs == true) }}

TODO: revert this before merging.

I'm proposing only updating the docs site on the builds triggered by merges to main. Just had this set to true to test this PR.

[jameslamb]

Suggested change

	- title: Main function (DELETE ME)
	- title: Main function

TODO: remove this before merging.

Put this here to prove that docs deployed this way are making it to the site: https://uptake.github.io/uptasticsearch/reference/index.html

[jameslamb]

Proposing using macOS because CRAN has pre-built binaries there. So CI is faster and less likely to fail with could-not-build-some-dependency-from-source types of errors.

The docs build takes around 3 minutes to run on macOS: https://github.com/uptake/uptasticsearch/actions/runs/13212614464/job/36888065982?pr=244

[austin3dickey]

This is so much better! Thanks!!

[jameslamb]

Thanks for taking a look!