Pass GitHub requirements for Xygeni Scanner action and publish it into GitHub marketplace

[lmrb-1968]

The Xygeni Scanner should be published in the GitHub actions marketplace for visibility. Perhaps List your tool on GitHub Marketplace is enough?

Although there is a Marketplace Badge for actions that looks easy to obtain, I do not know what documentation / configuration changes will be necessary.

For GitHub apps the requirements look much more strict.

[lmrb-1968]

Completed! Published v1.2 release