Clarify release flow

[jackshirazi]

The current release flow is

1. Run pre-release action, entering the version tag to release (1.2.3)
2. Approve the resulting PR
3. Merge that PR after tests have run
4. Run release action, re-entering the version tag to release (1.2.3) and skipping the first If enabled, the version bump, release notes update and tag creation will be skipped. Select this option if those tasks have already been done in a previous run section
5. Approve and merge the post release PR that merges to the 1.x branch, needed for the docs update (while the create github release action is waiting)

Suggested clarifications:

• rename pre release action to release-part1
• rename release action to release-part2
• rename pre post release action to release utility steps
• remove the skip_preparation steps and check from release.yml