Document how to use Dependabot to keep a test suite submodule up to date #549
Description
(Via @Relequestual here)
Implementers may appreciate a GitHub action which automatically sends PRs to their repo to update the test suite.
As a concrete example, python-jsonschema has a git-subtree of this suite here, and would benefit from automated pull requests whenever the main branch of this repository is updated.
To do this in general, such a github action would need to be configured with the path within a repo where the subtree lives, likely need to support both git-subtree as well as git-submodule (and possibly git-subrepo), and allow for passing options to the subtree/submodule command (e.g. if someone wanted a git subtree pull --squash to be the PR).
It's unclear that this should live in this precise repo rather than an adjacent one, but putting it here to track/ack the request.