Automatically write release tag to github SMUI code, on main commits and Dockerhub commits

[pbartusch]

WHAT?

Automatically write release tag to github SMUI code, on main commits and Dockerhub commits

[epugh]

I was trying to figure out versions wiht a client (they are on 3.14.0), and the alert is for 4.2.. However, going to https://github.com/querqy/smui/releases I don't see a 4.2, only a 4.0.11.....

I would love to help this move along....