Let's acknowledge everyone's contributions by replacing "Google LLC"
in the copyright header by "The Jujutsu Authors". If I understand
correctly, it won't have any legal effect, but maybe it still helps
reduce concerns from contributors (though I haven't heard any
concerns).
Google employees can read about Google's policy at
go/releasing/contributions#copyright.
Since whitespace change is barely visible in color-words diff, I think it
would be too verbose to add "\ No newline at end of file" marker. Let's just
append missing newline to make the command output readable.
