Hide ToC from the Apache Airflow doc main page

[drdenzy]

Fixes #12554 - #12561 addressed this by limiting the depth, but we can do better.

Before

After

Hide the ToC from being displayed when the
the index.rst file in the Apache Airflow docs is rendered.

This will improve user experience and prevent repetition of what has
already been displayed on the sidebar.

---

^ Add meaningful description above

Read the Pull Request Guidelines for more information.
In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
In case of a new dependency, check compliance with the ASF 3rd Party License Policy.
In case of backwards incompatible changes please leave a note in UPDATING.md.

[kaxil]

For now this looks good, however I think it would be good to have a separate page for just "TOC/Index"

[github-actions]

The PR is ready to be merged. No tests are needed!

[ashb]

The whole point is the ToC is in the sidebar of every page.

[kaxil]

The whole point is the ToC is in the sidebar of every page.

The problem with that is the sidebar hides nesting until you click on the level above it. So to have a TOC that shows all the index would still be better, though on a separate page. Definitely not on the main page.

Example:

https://airflow.readthedocs.io/en/stable/

https://airflow.readthedocs.io/en/stable/howto/index.html

https://airflow.readthedocs.io/en/stable/howto/operator/gcp/index.html

[mik-laj]

What do you think about moving the entire content to a separate sub-page with the title "Overview" and leaving the only a table of contents in the index.rst file?
Demo:
https://www.sphinx-doc.org/en/master/contents.html
https://sphinx-autoapi.readthedocs.io/en/latest/
The index.htmk website is very easy to access as it is not available in the TOC

[ashb]

Whops, just saw your comment as I hit merge @mik-laj, sorry!

[ashb]

I think index.html shouldn't be the index page, but some kind of welcome/intro -- it's often the first place people land, and going straight to "here's a load of links" isn't very helpful.

I have no problem with a separate contents page.

[mik-laj]

What do you think about having index.html to have a table of contents in TOC, but to give a liink to overview.html on s.apache.org/aiirflow-docs ?
The link to index.html is not available in the side menu and users are having trouble finding this page.

Do you know how to go to index.html while you are at tutorial.html?
http://apache-airflow-docs.s3-website.eu-central-1.amazonaws.com/docs/apache-airflow/latest/tutorial.html

[ashb]

I don't on our theme, but in the default RTD theme it's here:

(Anywhere on the "Airflow" on the home, or just the house icon on the right)

[ashb]

Testing a fix for this anyway @mik-laj.

Yup, that works: #12594