MithrilJS/mithril-node-render

Howdy @StephanHoyer! Apologies for the text dump, but I figured I'd reach out on gitter before opening a bunch of issues on github.

I have some free time this weekend, and I'd like to help out with mithril-node-render (and work towards some hacktoberfest swag :sweat_smile:).

If you're interested in any of the following ideas, I'll open some issues for more discussion, then I can work on some PRs:

1. Make the new isClass function match how Mithril itself checks for class components: i.e. classes don't have to actually use class syntax, they just need to be functions that have a view method on their prototype. This would simplify the check, and prevent possible incompatibilities between mithril and mithril-node-render.

2. Move mithril to a peerDependency: This is how react-dom and React Native handle their depedency on React, and would help prevent issues like #58 in the future. I imagine most users consuming this module probably already have mithril installed as a dependency, so you wouldn't run into the peerDependency hell that you do with e.g. eslint plugins and presets.

3. Update documentation a bit: There's a few minor grammar hiccups, and a couple areas that I think could use a bit more clarification (e.g. escaping).

4. Switch from co to async/await: this would be a breaking change and would only work on node >=8, but it would remove the dependency on co and I think make the code slightly more idiomatic.

5. Implement #65: I feel like this would be a pretty big change, but I could take a stab at implementing it as e.g. renderSync. With async/await becoming more mainstream, though, I don't know how relevant this still is?