This commit adds an `allowed_signers` file for public usage which can be
used in lieu of manually adding my public keys to personal
`allowed_signers` files.
This commit renames my SSH public keys and their respective signatures
to a user-friendly convention rather than the internal names used on my
systems.
This commit adds all of my SSH public keys and their respective
signatures. Each key is signed with the previous key, down to the 0th
key, which is the root-of-trust
