Roughness

Hello! Love this library - we use it on the home page of Exercism and I'm currently adding it to Kaido too

I'd like to make the lines slightly less rough, and was wondering if you'd be interested in a PR that allows consumers to vary the roughness option via the options hash? ie make this configurable: https://github.com/rough-stuff/rough-notation/blob/668ba82ac89c903d6f59c9351b9b85855da9882c/src/render.ts#L11

Thanks! :)