Update archiving-public-repositories.md

added note about the importances of not deleting a repository due to impact on the fork network

Author: Jeffrey-Luszcz

docs/archiving-public-repositories.md

@@ -19,3 +19,5 @@ In order to archive a github organization repository:
 3. Let it sit until you receive confirmation from a maintainer or an adequate length of time has passed.
 
 4. Close all open issues and pull requests and archive the repository from the repository settings.
+
+Note: It is important to typically choose to **Archive** unmaintained repositories instead of deleting them. When you delete a public repository, the oldest, [active public fork is chosen to be the new upstream repository](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/what-happens-to-forks-when-a-repository-is-deleted-or-changes-visibility). All other repositories are forked off of this new upstream and subsequent pull requests go to this new upstream repository. This may have security and reputational risks to your organization. If you must delete a repository, work with your OSPO or similar team to understand the implications of this process.