Adjust documentation webpage layout to be compatible with RTD addons

[r0qs]

Read The Docs will be enabling addons by default on October 7, 2024 and this will break the docs layout. See images below and also this link with the layout changes introduced with the addons: https://about.readthedocs.com/blog/2024/04/enable-beta-addons/

Relevant changes related to the documentation web page layout:

Visual changes

Even if the build has completed successfully, there may be some visual changes.
Version and pull request notifications were completely re-designed and the flyout menu has been moved to a floating position in
the bottom right, for example.

Depending on your project's configuration, the documentation tool and the theme you are using, you will notice these differences.
We plan to release a new version of our theme to keep the flyout menu at the bottom left integrated with the navbar soon,
and we are talking to other theme authors to communicate these changes and work with them towards a better integration.
Expect news around this visual changes in the following months.

In our case, the main doc page layout, the flyout panel and the search bar may need to be adjusted.

Maybe @wackerow could take a look on that? Maybe it is just a matter to adjust the sphinx_rtd_theme?

[wackerow]

Thanks for surfacing @r0qs... can try to find some bandwidth to take a look at this.

[r0qs]

I also reviewed the possible changes needed for our Sphinx configuration since RTD will no longer be handling these themselves. It appears we don't need to make any changes there. After enabling the addons on the RTD dashboard, only the layout was affected, as far as I could see.

[humitos]

It seems this was fixed yesterday in https://github.com/ethereum/solidity/pull/15485