zimbra-foss-builder repo is split

[adrian.gibanel.btactic]

zimbra-foss-builder has been split between zimbra-foss-builder and zimbra-foss repos.

- Zimbra FOSS Builder (from Maldua) let's you build Zimbra FOSS thanks to a custom script and some Dockerfiles. You can build Zimbra with or without Pimbra patches.
- Zimbra FOSS (from Maldua) will be aimed at storing the different Maldua's Zimbra FOSS releases, issues and associated documentation.

Feedback about this split (something that does not work as expected or it's not found in the proper repo) is welcome.