Update Release Doc

[rafvasq]

Update the release doc to include instructions for the following:

• Cherry-picking when necessary
• Updating FVT pre-pull image tags for version instead of latest
  see: 439b03a
  done in doc: Update docs for release v0.11.0 #414

Originally posted by @ckadner in #406 (comment)

[ckadner]

A few quick notes:

• set the the git committer to "GitHub" before doing any cherry-picking or re-basing:

  export GIT_COMMITTER_NAME="GitHub"
  export GIT_COMMITTER_EMAIL="noreply@github.com"
  

• do cherry-pick any new commits from main onto the release-* when creating new release candidates (rc1, rc2, ...) on the modelmesh-serving repo (only). Use the -x option to append the commit messages with the line "(cherry picked
  from commit …)":

  git checkout release-0.11
  git cherry-pick -x ..main
  git push
  

• for the other repos (modelmesh, modelmesh-runtime-adapter, ...), if there are no divergent commits on the release-* branch, use git rebase from master

  git checkout release-0.11
  git rebase main
  git push
  

• don't rebase the release-* branches after a ...-rc0 tag had been created, it would remove the commit that was used for the previous rc tag

[ckadner]

We should also add a bit of text to describe the chicken-and-egg problem with kserve/kserve requiring the new ModelMesh release before creating it's new release (kserve/kserve#3059), but modelmesh-serving depending on the new KServe release so that it can create a new release (#413).

On the kserve/kserve side, the requirement is for the tagged Docker images to be available. To get those ModelMesh images before ModelMesh creates a new tagged release, the existing RC images can be retagged, assuming there were no (major) code changes since the last release candidate.

old_tag="v0.11.0-rc1"
new_tag="v0.11.0"

images=(
   modelmesh
   modelmesh-controller
   modelmesh-minio-dev-examples
   modelmesh-minio-examples
   modelmesh-runtime-adapter
   rest-proxy
)

for img in ${images[*]}; do
  # use `buildx imagetools` instead of `docker manifest` to maintain multi-arch manifests
  docker buildx imagetools create \
    "kserve/${img}:${old_tag}" --tag \
    "kserve/${img}:${new_tag}";
done