Reorganization of the Sphinx docs to only include reference pages

[miguelgrinberg]

Reorganization of the Sphinx docs to only include reference pages.

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[pquentin]

LGTM, but we should wait for HTTP redirects to be in place before merging IMO.

Including a redirect from /api.html to /index.html.

[miguelgrinberg]

@pquentin Redirect table proposal:

source	target
/en/latest/	No change
/en/latest/quickstart.html	https://www.elastic.co/guide/en/elasticsearch/client/python-api/master/getting-started-python.html
/en/latest/interactive.html	https://www.elastic.co/guide/en/elasticsearch/client/python-api/master/examples.html
/en/latest/api.html	/en/latest/index.html
/en/latest/exceptions.html	No change
/en/latest/async.html	https://www.elastic.co/guide/en/elasticsearch/client/python-api/master/async.html
/en/latest/helpers.html	https://www.elastic.co/guide/en/elasticsearch/client/python-api/master/client-helpers.html

The api.html, async.html and helpers.html exist in both old and new designs. Would it make sense rename these pages in the redesigned docs, so that we can add the redirects above and also have pages we can link from now on?

And aside from this, it is unfortunate but I think we are going to have to create redirects for each version that we publish, until we decide this isn't necessary anymore, because we want the <= 8.17 docs to be redirect free, meaning that we cannot do generic redirects across all versions.

[pquentin]

The api.html, async.html and helpers.html exist in both old and new designs. Would it make sense rename these pages in the redesigned docs, so that we can add the redirects above and also have pages we can link from now on?

Yes, good point.

And aside from this, it is unfortunate but I think we are going to have to create redirects for each version that we publish, until we decide this isn't necessary anymore, because we want the <= 8.17 docs to be redirect free, meaning that we cannot do generic redirects across all versions.

That makes sense. The free plan we're using allows for 100 redirects, but I'm assuming we will only need redirects for latest, stable, 8.18, 8.19, 9.0 and 9.1, not much more than that?

[miguelgrinberg]

All pages renamed so that there are no collisions with the redirects. I guess we can wait until the new docs system is in place to see if the redirects above need to be adjusted, and only merge this PR after we put those in.