DOC: add placeholder for announcement banner in docs (and use for 3.0rc announcement)

[jorisvandenbossche]

Would have to refine the actual message for right now, but general idea is that it would look like this:

The banner disappears once you scroll down, but is otherwise always visible (there is no "x" to click it away). You can see a live version of it on the theme docs: https://pydata-sphinx-theme.readthedocs.io/en/stable/index.html

Thoughts?

[jorisvandenbossche]

And because it is set up with a URL (not hardcoded text in the docs itself), once this is included on the hosted docs, you can change or disable (with empty file) the banner by changing the template file in the main repo, without having to rebuild the docs.

[mroeschke]

I'm +0.5 on including this. Personally, the banner appearing on every page of the docs without a way for visitors to suppress it is a shame, but the announcement is important for us

[mroeschke]

Should the URL point to https://pandas.pydata.org/docs/dev/whatsnew/v3.0.0.html instead? Visiting https://pandas.pydata.org/docs/whatsnew/v3.0.0.html directly 404's for me

[jorisvandenbossche]

Yes, indeed (it was just some quick content, should still have to wordsmith and format an actual messsage)

[jorisvandenbossche]

Personally, the banner appearing on every page of the docs without a way for visitors to suppress it is a shame, but the announcement is important for us

It would have been nicer that it is "dismissible" indeed .. But if we only show it for a few weeks, I think that is OK? Or at least worth a try. As I mentioned, we can always easily disable it by committing something to main

[jorisvandenbossche]

There is pydata/pydata-sphinx-theme#1384 about making it dismissable, but that is not yet implemented. But it is done for the version banner (pydata/pydata-sphinx-theme#1763), maybe I can reuse some parts there to add some javascript on our side to add a close button.

[mroeschke]

Yeah just sharing a non-blocking opinion. OK with the banner generally