This adds a new settings, SOCIAL_AUTH_SUBDOMAIN, which specifies which
domain should be used for GitHub auth and other python-social-auth
backends.
If one is running a single-realm Zulip server like chat.zulip.org, one
doesn't need to use this setting, but for multi-realm servers using
social auth, this fixes an annoying bug where the session cookie that
python-social-auth sets early in the auth process on the root domain
ends up masking the session cookie that would have been used to
determine a user is logged in. The end result was that logging in
with GitHub on one domain on a multi-realm server like zulipchat.com
would appear to log you out from all the others!
We fix this by moving python-social-auth to a separate subdomain.
Fixes: #9847.
This is what the Sphinx docs recommend when you actually don't want
the page to be included in navigation:
http://www.sphinx-doc.org/en/stable/markup/toctree.html
And now that we have `eval_rst`, we're able to take advantage of it!
One difference between doing this and the old way of making "hidden"
toctree entries is that with the latter, the "previous" and "next"
links at the bottom of each page would thread through the hidden
entries; which gets kind of confusing when they don't appear in the nav.
This commit helps reduce clutter on the navigation sidebar.
Creates new directories and moves relevant files into them.
Modifies index.rst, symlinks, and image paths accordingly.
This commit also enables expandable/collapsible navigation items,
renames files in docs/development and docs/production,
modifies /tools/test-documentation so that it overrides a theme setting,
Also updates links to other docs, file paths in the codebase that point
to developer documents, and files that should be excluded from lint tests.
Note that this commit does not update direct links to
zulip.readthedocs.io in the codebase; those will be resolved in an
upcoming follow-up commit (it'll be easier to verify all the links
once this is merged and ReadTheDocs is updated).
Fixes#5265.