Update PA handbook with community contribution disclaimer

Why is this change being made?

Provide a detailed answer to the question on why this change is being proposed, in accordance with our value of Transparency.

Please add the details saying why, not just what in this section. Example: We have discussed the topic in Slack - (copy of Slack conversation). The current process is not efficient, this MR makes the description of X more clear, and helps move Y forward.

This change has been introduced to have clear guidance on Better handling community contributions.

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added, and the content is SAFE
• Assign reviewers for this MR to the correct Directly Responsible Individual/s (DRI)
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies
  • The when to get approval handbook section explains the workflow in more detail
• For transparency, share this MR with the audience that will be impacted.
  • Team: For changes that affect your direct team, share in your group Slack channel
  • Department: If the update affects your department, share the MR in your department Slack channel
  • Division: If the update affects your division, share the MR in your division Slack channel
  • Company: If the update affects all (or the majority of) GitLab team members, post an update in #whats-happening-at-gitlab linking to this MR
    • For high-priority company-wide announcements work with the internal communications team to post the update in #company-fyi and align on a plan to circulate in additional channels like the "While You Were Iterating" Newsletter

Commits

• Update file _index.md

---

content/handbook/engineering/development/ops/verify/pipeline-authoring/_index.md

@@ -118,6 +118,28 @@ We highly value user feedback! Please use the issue below to capture feedback an
 
 - [CI/CD Catalog Feedback](https://gitlab.com/gitlab-org/gitlab/-/issues/407556)
 
+## Community Contributions
+
+Pipeline authoring at GitLab involves a deep understanding of our CI/CD system and its intricate interactions with various components. This complexity can present challenges for those unfamiliar with the codebase and underlying architecture.
+
+We encourage community contributors to work on issues with the ~"seeking community contribution" label. These issues are specifically selected to provide a clear and manageable path for external contributions.
+
+Due to the inherent complexity of pipeline authoring, contributions to issues not marked for community contribution may require significant domain knowledge and familiarity with GitLab's internals. While we appreciate all contributions, Merge Requests for these issues may require more extensive review and may not be merged if they don't align with our architectural vision or best practices.
+
+### Guidance for Reviewers
+
+When reviewing Merge Requests from community contributors, please consider the following:
+
+- Issue Selection: Verify if the contribution addresses an issue labeled ~"seeking community contribution". If not, assess the complexity and required domain knowledge.
+- Mentorship: If the contribution shows promise but needs guidance, provide constructive feedback and consider offering mentorship to help the contributor succeed.
+- Clear Communication: Explain the rationale behind any required changes or decisions clearly and respectfully, ensuring the contributor understands the context and reasoning.
+
+If the issue picked up by the community does not have the ~'seeking community contribution' label and/or is too complex please consider using the following template:
+
+```markdown
+"Thank you for your interest in contributing to GitLab! We appreciate you taking the initiative to work on this. This particular area involves complexities that may require deeper domain knowledge of GitLab's CI/CD system. To ensure a smoother review process and increase the likelihood of your contribution being merged, we recommend focusing on issues with the ~'seeking community contribution' label. These are specifically curated for external contributors. A curated list of issues is available here: https://gitlab.com/gitlab-org/gitlab/-/issues/?sort=popularity&state=opened&label_name%5B%5D=group%3A%3Apipeline%20authoring&label_name%5B%5D=Seeking%20community%20contributions&first_page_size=100"
+```
+
 ## Group Meetings
 
 For every meeting, it is expected that it contains a list of agenda items to discuss along with the meeting notes when the meeting takes place. This will make it easier for people to catch up if they are unable to attend.