Update to a later version of the template

[chillenzer]

We are missing the links to individual tasks and sections inside an episode and should update to a later template. Maybe not the latest because I think they've recently reworked it completely. Don't know about how much work that would be.

[edbennett]

In principle it should be as simple as adding https://GitHub.com/carpentries/styles as a remote and then merging in the gh-pages branch.