Merge branch 'mr/worktree-list'

Add the "list" subcommand to "git worktree".

* mr/worktree-list:
worktree: add 'list' command
worktree: add details to the worktree struct
worktree: add a function to get worktree details
worktree: refactor find_linked_symref function
worktree: add top-level worktree.c

diff --cc Makefile
Simple merge