It looks like mkdocstrings will fail out if it can't download the inv files.
Unless there's a setting where you can tell it "try, but if you can't grab
them just don't try and create links" the approach here seems reasonable and
has the same effect.
https://github.com/Textualize/textual/issues/2629#issuecomment-1566672594
for reference.
The idea here is that there is a single file for the nav for all the docs,
both online and offline. The nav will be the full online nav in all its blog
glory, and then the build system will strip out the nav items relating to
the blog when building the offline version.
There's a wrinkle or two still in here; the main one being that when doing a
docs-serve, it seems that the cleaning up of the online nav doesn't happen
when you Ctrl-C out of the server. I'm not 100% sure of the cause of
this (there could be a couple of different reasons).
For now... I'm ensuring that the online/offline nav files are excluded from
git. It would be nice to find out how best to always ensure that the online
nav file is removed so nobody attempting to update the docs gets confused
about what to edit.
