Merge branch 'sb/worktree-remove-opt-force'

"git worktree remove" learned that "-f" is a shorthand for
"--force" option, just like for "git worktree add".

* sb/worktree-remove-opt-force:
  worktree: accept -f as short for --force for removal

diff --cc Documentation/git-worktree.txt
Simple merge

diff --cc builtin/worktree.c
Simple merge