Document badges in Apify Store

[szaganek]

Move the article that's currently in Academy:

• https://docs.apify.com/academy/actor-marketing-playbook/store-basics/how-store-works

Also some info here: https://help.apify.com/en/articles/6999799-what-are-apify-maintained-and-community-maintained-actors

A new badge is coming soon.