Feature Request: Config option to always compile to text/html (i.e. without !m sigil)?

[rlue]

I've been looking for something like muttdown for years now, and am so pleased to have found it! Thanks so much for you work, really.

I'd like to be able to configure muttdown to compile every single email I write into multipart/alternative without having to prefix messages with !m. Is there any chance you'd be willing to add a config or command line option to that effect? I'd take a stab myself, but I haven't had much of a chance to work with Python yet, and I suspect my contributions wouldn't be exemplary or idiomatic.