Vagrant VM: Add `cd /vagrant` to ~/.profile

If you follow the Discourse Developer Install Guide (Vagrant), you will always need to cd /vagrant after vagrant ssh.

Therefore I added this command to the ~/.profile within the Vagrant VM, so that I never have to do that anymore:

$ vagrant ssh
$ echo "cd /vagrant" >> ~/.profile

I was wondering: Could we add this to the VM by default? Or add this hint to the guide?