Merge pull request DjangoGirls#459 from willingc/patch-1

Suggest user friendly edits for Extend chapter

🐍🌏 Switched to PythonAnywhere for the deploy chapter.

Thanks to Harry Percival for the huge amount of work and
to all the contributors who helped review this chapter.

A copy of the full commit history of this can be found
on the posterity/python-anywhere-rewrite.

Merge branch 'master' of github.com:DjangoGirls/tutorial

Test gitbook integration commit DjangoGirls#1.