Git Crypt enables transparent encryption and decryption of files in a git repository. See also:
git-crypt
. More information: https://github.com/AGWA/git-crypt.
yadm git-crypt init
yadm git-crypt add-gpg-user user_id
yadm git-crypt unlock
yadm git-crypt export-key path/to/key_file