docs: update repo captain nomination policies

Ref: #6234 (comment)

Author: UlisesGascon

Contributing.md

@@ -132,12 +132,19 @@ Like TC members, Repo captains are a subset of committers.
 To become a captain for a project the candidate is expected to participate in that
 project for at least 6 months as a committer prior to the request. They should have
 helped with code contributions as well as triaging issues. They are also required to
-have 2FA enabled on both their GitHub and npm accounts. Any TC member or existing
-captain on the repo can nominate another committer to the captain role, submit a PR to
-this doc, in the **Active Project Captains** section (maintaining the sort order) with
-the project, their GitHub handle and npm username (if different). The PR will require
-at least 2 approvals from TC members and 2 weeks hold time to allow for comment and/or
-dissent.  When the PR is merged, a TC member will add them to the proper GitHub/npm groups.
+have 2FA enabled on both their GitHub and npm accounts.
+
+Any TC member or an existing captain on the **same** repo can nominate another committer 
+to the captain role. To do so, they should submit a PR to this document, updating the 
+**Active Project Captains** section (while maintaining the sort order) with the project 
+name, the nominee's GitHub handle, and their npm username (if different).
+- Repos can have as many captains as make sense for the scope of work.
+- A TC member or an existing repo captain **on the same project** can nominate a new captain. 
+  Repo captains from other projects should not nominate captains for a different project.
+
+The PR will require at least 2 approvals from TC members and 2 weeks hold time to allow 
+for comment and/or dissent.  When the PR is merged, a TC member will add them to the 
+proper GitHub/npm groups.
 
 ### Active Projects and Captains