Fix bug in directory summarization
Print "??" status only if no other status exists

E.g. print "R ", not "??" if the file is renamed then untracked
file with same filename created.
Print "*" mark just after filename

E.g. `git mv old_fn new_fn && touch old_fn`

Before:
    "old_fn -> new_fn*"
Now:
    "old_fn* -> new_fn"
Merge branch 'feature/better-summary' into develop
Add readme/screenshot