Almost everyone calls the project "jj", and there seeems to be
consensus that we should rename the crates. I originally wanted the
crates to be called `jj` and `jj-lib`, but `jj` was already
taken. `jj-cli` is probably at least as good for it anyway.
Once we've published a 0.8.0 under the new names, we'll release 0.7.1
versions under the old names with pointers to the new crates names.
We used to have documention about how conflicts are implemented, but I
removed that a long time ago when I rewrote the README to target users
rather than VCS hackers. Let's have a doc for the VCS hackers (and
curious users) as well, though.