I manage some of my projects already in GitHub. For example Tealight which is also in catalog.
Anything you have to do is
1) to create a “tag” in git (see https://stackoverflow.com/questions/18216991/create-a-tag-in-github-repository), I name the tags with the according version number like 0.0.2 following semantic versioning (http://semver.org)
2) provide a ConfigurationOf (as you had in the past) where the “version” references the “git tag” with the same name
a) also #stable has to point to the “version” as it was in the past
optional: b) the #development should point to the Baseline in the git branch that you typically use for development (this allows for loading of bleeding edge as before)
3) upload the Configuration to a MetaRepo as before to appear in catalog
1) I have two tagged versions for Tealight on Git (0.0.1 and 0.0.2)
2) In my ConfigurationOfTealight (which I also manage in git) I reference the tag, for example in version 0.0.2 I reference the tag with the same name “github://astares/Tealight:0.0.2/repository”:
Side note: a) now you can use your #stable definition in the ConfigurationOf as before https://github.com/astares/Tealight/blob/master/repository/ConfigurationOfTealight.package/ConfigurationOfTealight.class/instance/stable..st
b) Your #development definition should point to the master branch (or whatever the development branch is)
Iceberg is managed in a similar way (but is now included in the image and the catalog part is only for compatibility).
Hope this helps.