Fix link to my tutorial

[steveklabnik]

steveklabnik/jujutsu-tutorial@2d62f22 reorganized some things, and so this link became broken

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[steveklabnik]

I don't know how to re-run the CLA check, but I've signed it.

[PhilipMetzger]

should be good now, I accidentally re-ran all checks.