ReadTheDocs notifications for PR builds and older versions do not show up

[laymonage]

Not sure how to fix this yet, but it seems we no longer have the admonition that shows up on PR builds and older versions:

I manually edited that in Wagtail's docs to demonstrate. This used to show up automatically. I think it's added by RTD's script.

The admonition not showing up anymore might be related to the new Read the Docs Addons enabled by default, and that some injected Sphinx context has been removed: readthedocs/readthedocs.org#11474

It seems RTD is moving towards this new Notification add-on:

Which I believe comes from this setting on the dashboard:

However, that new notification popup at the top right seems to only trigger in old versions of Wagtail's docs where we still used RTD's theme:

• https://docs.wagtail.org/en/v2.12.5/ RTD theme, new toast notification shows up
• https://docs.wagtail.org/en/v2.13.5/ our theme, toast notification does not show up

This leads me to believe there's something in our theme that's causing the toast notification not to show up.

Also, not sure if this is related, but as you can see the old-style admonition doesn't show up in the v2.12 docs. However, in the v2.2 docs https://docs.wagtail.org/en/v2.2.2/, you can see both the old-style admonition and the new toast notification.

[laymonage]

Turns out the element is there – but again, Bootstrap messes with it because RTD uses a generic .toast class rather than a namespaced class name.

See opacity: 0; at the bottom right.

I've raised readthedocs/addons#413.

Maybe it's time we move away from Bootstrap too, as noted in #254 (comment)...

[laymonage]

Fixed in #299