Clarified team admin capabilities (#7681)

source/collaborate/learn-about-roles.rst

@@ -44,7 +44,7 @@ When a team is first created, the person who set it up is made a team admin. It
 - Access to the **Team Settings** menu.
 - Ability to change the team name and import data from Slack export files.
 - Access to the **Manage Members** menu, where they can control whether team members are a **Member** or a **Team Admin**.
-- Ability to manage all aspects of a team, such as managing private channels they're not a member of.
+- Ability to manage all aspects of a team, such as joining and managing private channels they're not a member of.
 
 Channel admin
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