doc: committing someone else's change: not always straightforward

'./rbt patch -c 123' doesn't always work, so don't suggest
it so prominently

Testing Done:
Trying out the steps on this very commit.

Reviewed at https://rbcommons.com/s/twitter/r/699
Merge branch 'master' into stuhood/sorted-targets
Use transitive deps rather than direct deps for reordering check