Create/Update the instructions for syncing release branches with upstream

[heyselbi]

In branching strategy it was decided that we want to be upstream first. As a follow up action, a set of instructions and a template needs to be created/updated for all of the steps involved in syncing release branches of all repos that we manage with upstream/release. This should also indicate how often this will happen and what needs to be done for RHODS as well.

[israel-hdez]

KServe template: opendatahub-io/kserve#87

[israel-hdez]

ModelMesh template: #211