docs: Add release-specific branch info
Add release-specific branch docs.
With the latest decision of making VTK (A major user of VTK-m) to depend on specific versions of VTK-m rather than arbitrary commits and to link VTK releases with VTK-m releases (for instance: VTK 9.1.X depends on VTK-m 1.7.X; 9.2.X depends on 1.8.X) we need a way to possibly to support older VTK-m releases to cover the gaps of time between the two projects.
The natural solution is to introduce release branches when the circumstances are required, such as requested here. For that purpose I propose the following scheme (As Extracted from this MR docs changes):
Sometime we need to keep maintaining an older release which does not sit at the tip of the release branch. For this purpose we use release-specific branches with the name of
v@MAJOR_VER@.@MINOR_VER@.To create a new release-specific branch you need somebody with push access to push this release-specific branch pointing at the latest tag corresponding for this minor release, this is, for v1.7 it will be v1.7.1 as opposed to v1.7.0.
To add a HotFix to a release-specific branch, follow the instructions described in HotFixes noting that you need to adjust the branch names from release to
v@MAJOR_VER@.@MINOR_VER@.