Include a link to the hosted documentation in the repository details

It's a little bit tricky to find the docs currently. I didn't realise there were any until I found them via google search. You can add a link to the repo details by clicking the gear (⚙️) icon next to "about" on the LHS of the repo homepage

Start at the rules_pkg repository homepage and locate the hosted documentation site, then open the repository details through the gear icon beside “About.” Add the documentation link to the repository details and confirm that it is visible from the repository homepage.

Written by the indexing model from the issue text.