Feature Request: Global defaults

[leafac]

Great library, y’all 🙌

I propose we add something like:

MicroModal.defaults = { disableScroll: false };

I’d find that useful because I’m not using MicroModal.init(). Instead I put MicroModal.open() on the onclick of my buttons. Right now I have to do something like MicroModal.open(<target>, microModalDefaults), where microModalDefaults is a global variable.

If you like the idea please let me know and I may work on a Pull Request.