The purpose of anonssh-git is to let you clone any GitHub repo using SSH
instead of HTTPS, even on machines which don't have your ~/.ssh/id_rsa.
This is ideal because OpenSSH is less buggy than SSL libraries, and has a
security model that does not let rogue or compromised certificate authorities
MITM your git clone/fetch.
anonssh-git uses a publicly-known "private" key registered to https://github.com/anonssh-keys, and the key (like any other registered to GitHub) can be used to clone any repo.
To configure ~/.ssh/config to use this key and also add GitHub's host
fingerprint to ~/.ssh/known_hosts, run ./install-anonssh-config.
If you already have a Host github.com in ~/.ssh/config, it will not
change config. You should not use this key on machines from which
you push code to GitHub, because cloning using your own SSH key will work fine.
To use the git wrapper that converts git clone https://github.com/x/y to
git clone git@github.com/x/y, run anonssh-git or alias git=anonssh-git.