[TW5] How can you make markdown the default when creating from missing tiddler?

[Richard Batty]

I have installed the markdown plugin and I have the 'create a new markdown tiddler' which works fine. But when I create a link to a tiddler that doesn't exist, then click on it, and I get the "missing tiddler ... click to create", and then I click the edit button to create, it creates a wiki syntax tiddler.

How can I get it to default to creating markdown tiddlers?