Update version of Vagrant from 1.8.6 to 2.0.2.
Update version of VirtualBox from 5.1.8 to 5.2.6.
We needed to update Vagrant because older versions have networking
problems on modern Macs, resulting in weird `apt` errors when
provisioning.
Commit message and some text tweaked by tabbott.
This updates the developer documentation to recommend `git clone -c`
to set the git pull mode to be rebase by default in the repository
configuration.
The hope is that this will help minimize how often new contributors
end up accidentally messing up their PRs by using `git pull`.
Tweaked by tabbott to fix broken links and optimize the language.
Fixes: #7022.
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.
Tim Abbott
Shivam Gera
Aman Agrawal
Jeremy Zhou
Harshit Bansal
Mohd Ali Rizwi
KiranS
David Rosa Tamsen