Update developer documentation with information on committers and contributors can collaborate
We should update the developer documentation to explain how the committers can work with contributors:
- How go get a merge request from a contributors fork into your own Git repository. See e.g. https://docs.gitlab.com/ee/user/project/merge_requests/reviewing_and_managing_merge_requests.html#checkout-merge-requests-locally-through-the-head-ref
- How to add commits as a committer to a contributors merge request to address review comments.
- How contributors can update their forked repository when the official Eclipse ESCET GitLab repo is updated. See e.g. https://forum.gitlab.com/t/refreshing-a-fork/32469/2. Section 'Git CLI' would be good to try. Section 'GitLab Repository Mirror' won't work, as it requires admin rights on the Eclipse Foundation GitLab.
- How committers and contributors can work together, allowing both the contributor and committer to add new commits. See also https://www.eclipse.org/lists/escet-dev/msg00105.html
- How to manually check whether contributors have an ECA on file, just in case of issues with the automatic checks. I.e. use the ECA Validation Tool at https://accounts.eclipse.org/user/eca.
CONTRIBUTING.asciidocin the Git repo root mentions https://gitlab.eclipse.org/eclipse/escet/escet/-/merge_requests, which contributors can't use, as they need to create a merge request from their own fork. This is confusing information.