It is automatic -- it crawls projects' bug trackers. That way, projects can mark bugs as "good for newcomers" without us forcing them to use new tools.

Having said that, the site does give projects a space to write about ways people can get involved beyond what's in the bug trackers. You can see at https://openhatch.org/+projects/Gally that a project maintainer requested something rather unique: a call for videos of people signing individual words in American Sign Language.