Change notes: Markdown as an interchange format

Various tools-for-thought products use Markdown as an interchange format for outlines. #

Whatever I personally think of the format, there's enough support out there so that it's wise for Drummer to support the format if possible.#

I've started writing some code to do it, starting with export.#

Here's the thread on the RFC site. #

Here's a demo, the serialization of the states outline. #