Stable version of MXD

[ndr-brt]

Currently main branch is not stable, we should decide how to provide stable MXD versions to community:

• keep main stable
• keep main unstable and release stable version (as done in MVD)

[bmg13]

Hey, I would support having periodic stable releases and am okay with main being temporarily unstable. So would support the option similar to MVD.

[lgblaumeiser]

I support the idea of having stable versions available. As @bmg13 does, I would prefer the second option as done in MVD. Having clear tags that are assumed to work is a widespread known concept. A working main is not that common. In addition, we could still use main to update continuously to the current snapshots what could be of use in certain situations.