This commit renames various source requirements files like `dev.txt`,
`mypy.txt` etc to `dev.in`, `mypy.in` etc and various locked requirements
files like `dev_lock.txt`, `mypy_lock.txt` etc to `dev.txt`, `mypy.txt`
etc. This will help in emphasizing to the user that *.in are actually
input to `update-locked-requirements` tool which should be run after
updating any of these.
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.
Harshit Bansal
David Rosa Tamsen