Add versions and releases

[maxhbr]

We need to add releases to this repository.

Maybe we should also add a disclaimer like

Release Pattern

This project does not follow semantic versioning - version numbers are kept matching to the minimum compatible product version

[maxhbr]

@mcjaeger @alex-evo would it be ok to simply tag the current commit to be "1.5.0" and to add the disclaimer?

[alexbrdn]

fine with me