alternative schedule.ejs templates

[paciorek]

@andrewpbray and I discussed having various schedule ejs templates in this repo. I think each one might have an (optional) corresponding style file.

How do we want to organize this - just vary the names, e.g., schedule-scf.ejs and styles-scf.css or something else? I suppose we could have a subdirectory for each.

We'll also presumably want an example schedule.yml at the top level of the repository corresponding with each schedule.ejs, since the structure/keys will generally change a bit.

[paciorek]

@andrewpbray just a ping to request your input on naming. I'd like to add the template we've been using for stat course websites here but was hoping we could decide on naming first.