v0.12.0

In this release, we're launching a major redesign of the block-based editor for Wordplay. It breaks convention from other drag-and-drop editors by supporting drag-and-drop, menus, and text editing.

It's not yet perfect — there are things to polish here and there — but it is better than the previous version (in that it's usable), and so we're launching it to get feedback. Tinker with it and see if you can find ways of improving it.