My month counts says see the documentation for more information. Maybe I am blind, but I do not know what documentation is mentioned. Could you please link it?
OFF questions; Logging in works for yourself, no answer needed
Plus, creating User:Bencemac/EditCounterOptIn.js on a wiki will turn it ON for every project? Can we choose (e.g. I want top edited pages, just only that)?
Thanks for raising this issue! There are now links included in the messaging.
creating User:Bencemac/EditCounterOptIn.js on a wiki will turn it ON for every project? Can we choose (e.g. I want top edited pages, just only that)?
You can either add an EditCounterOptIn.js for the desired wikis, or do so globally at Special:MyPage/EditCounterGlobalOptIn.js on Meta. This is explained in the documentation, which of course you understandably were unable to find :)