Add top repo info to "About your personal dashboard" (#16237)

Closes github/docs-content#3132

Co-authored-by: Matt Pollard <[email protected]>
Co-authored-by: Shati Patel <[email protected]>

Author: 3 people

content/github/setting-up-and-managing-your-github-user-account/about-your-personal-dashboard.md

@@ -29,6 +29,8 @@ In the left sidebar of your dashboard, you can access the top repositories and t
 
 ![list of repositories and teams from different organizations](/assets/images/help/dashboard/repositories-and-teams-from-personal-dashboard.png)
 
+The list of top repositories is automatically generated, and can include any repository you have interacted with, whether it's owned directly by your account or not. Interactions include making commits and opening or commenting on issues and pull requests. The list of top repositories cannot be edited, but repositories will drop off the list 4 months after you last interacted with them.
+
 You can also find a list of your recently visited repositories, teams, and project boards when you click into the search bar at the top of any page on {% data variables.product.product_name %}.
 
 ### Staying updated with activity from the community