js/builtin-add-i, was Re: What's cooking in git.git (Nov 2019, #01; Mon, 4)

> * js/builtin-add-i (2019-08-30) 11 commits
>  . built-in add -i: implement the `help` command
>  . built-in add -i: use color in the main loop
>  . built-in add -i: support `?` (prompt help)
>  . built-in add -i: show unique prefixes of the commands
>  . Add a function to determine unique prefixes for a list of strings
>  . built-in add -i: implement the main loop
>  . built-in add -i: color the header in the `status` command
>  . built-in add -i: refresh the index before running `status`
>  . built-in add -i: implement the `status` command
>  . diff: export diffstat interface
>  . Start to implement a built-in version of `git add --interactive`
>
>  The beginning of rewriting "git add -i" in C.
>
>  Expecting a reroll on top of a base with the tg/stash-refresh-index
>  topic that defines an updated repo_refresh_and_write_index() helper.
>  cf. <20190911175201.GA11444@cat>