Fixes T9973. When users run arc land --hold, give them the commands to move forward (push) or backward (checkout the branch/tag/commit they were on) and be explicit that branches have not changed.
- Maniphest Tasks
- T9973: `arc land` detached head state with `--hold`
- rARC9a373c88d747: Explain how to move forward or backward from `arc land --hold`
Ran arc land --hold, got lots of explanatory text.