[Feature Request] Preview acitvation for .mkd files.

[habrown]

Great extension - making the transition from atom to brackets more streamlined!

However, I have a bunch of markdown files with file extension ".mkd", as opposed to ".md" or ".markdown"

As far as I know, .mkd is a commonly used file extension for markdown files.

Would you consider adding .mkd as a file extension that would activate MarkdownPreview?

Thank you!

[ijmitch]

It would be nice to be able to preview any file which the user has set the file extension to default to markdown handling in the base editor.