AFAIK, we can't make HEAD detached in an empty Git repository, so we need
to temporarily switch to the new default branch before checking out.
Fixes#2047
This makes it possible to use ed25519 and ed25519-sk keys by trying
them one at a time. However, it still fails if one of them is
password-protected; we don't try the next key in that case.
Summary: In preparation for unifying all workspace dependencies across all
crates, let's go ahead and move the jj-cli crate into its own new directory.
This will also be a nicer and more uniform layout as we add new `jj-*` crates.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Change-Id: Icf94e7ae5f290dc8e181215727b38ada