~/.gitconfig: Add freedesktop.org and bitbucket.org shortcuts.

.gitconfig

	insteadOf = gh:
[url "git@heroku.com:"]
	insteadOf = heroku:
[url "git://anongit.freedesktop.org/"]
	insteadOf = fd:
[url "git@bitbucket.org:"]
	insteadOf = bb: