Class-by-class descriptions

[eah13]

Make a special type of blog post that describes a class session, and list them while their date hasn't passed. This modularizes the big long list of class sessions in the schedule.

[eah13]

Related: the schedule just a list of just these posts, while the index is all the posts.

[eah13]

One problem with this plan: Jekyll can't sort ascending without a plugin, making gh-pages hosting a pain.

[gerbal]

Could use Javascript or Jquerry to rearrange the posts on the fly.

Or a pair of nested loops could do a simple stack-sort in liquid.