doc: GitHub PRs workflow

doc/userguide/devguide/codebase/contributing/github-pr-workflow.rst

@@ -0,0 +1,46 @@
+GitHub Pull Request Workflow
+============================
+
+Draft Pull Requests
+~~~~~~~~~~~~~~~~~~~
+
+A Pull Request (PR) should be marked as `draft` if it is not intended to be merged as is,
+but is waiting for some sort of feedback.
+The author of the PR should be explicit with what kind of feedback is expected
+(CI/QA run, discussion on the code, etc...)
+
+GitHub filter is ``is:pr is:open draft:true sort:updated-asc``
+
+A draft may be closed if it has not been updated in two months.
+
+Mergeable Pull Requests
+~~~~~~~~~~~~~~~~~~~~~~~
+
+When a Pull Request is intended to be merged as is, the workflow is the following:
+ 1. get reviewed, and either request changes or get approved
+ 2. if approved, get staged in a next branch (with other PRs), wait for CI validation
+    (and eventually request changes if CI finds anything)
+ 3. get merged and closed
+
+A newly created PR should match the filter
+``is:pr is:open draft:false review:none sort:updated-asc no:assignee``
+The whole team is responsible to assign a PR to someone precise within 2 weeks.
+
+When someone gets assigned a PR, the PR should get a review status within 2 weeks:
+either changes requested, approved, or assigned to someone else if more
+expertise is needed.
+
+GitHub filter for changes-requested PRs is ``is:pr is:open draft:false sort:
+updated-asc review:changes-requested``
+
+Such a PR may be closed if it has not been updated in two months.
+It is expected that the author creates a new PR with a new version of the patch
+as described in :ref:`Pull Requests Criteria <pull-requests-criteria>`.
+
+Command to get approved PRs is ``gh pr list --json number,reviewDecision --search
+"state:open type:pr -review:none" | jq '.[] | select(.reviewDecision=="")'``
+
+Web UI filter does not work cf https://github.com/orgs/community/discussions/55826
+
+Once in approved state, the PRs are in the responsibility of the merger, along
+with the next branches/PRs.

doc/userguide/devguide/codebase/contributing/index.rst

@@ -6,3 +6,4 @@ Contributing
 
     contribution-process
     code-submission-process
+    github-pr-workflow