branching - switch to same naming scheme as ERPNext

[dulhaver]

I am wondering whether it makes sense to follow the switch to version-11, version-12 naming scheme for this app.

The advantage would be that this

1. gives confidence to users to be on the correct branch
2. opens the opportunity to fix branch specific problems (or, if fixes can't be done for eatch stable ERPNext branch, at least make clear which ERPNext branch it may have problems with)