worktree.guessRemote::
If no branch is specified and neither `-b` nor `-B` nor
`--detach` is used, then `git worktree add` defaults to
creating a new branch from HEAD. If `worktree.guessRemote` is
set to true, `worktree add` tries to find a remote-tracking
branch whose name uniquely matches the new branch name. If
such a branch exists, it is checked out and set as "upstream"
for the new branch. If no such match can be found, it falls
back to creating a new branch from the current HEAD.