Convert to typescript?

Would there be any interest in converting the "source" of this repo to typescript? Right now it's coffeescript, but there is a typescript implementation for deno.

Right now using omelette with typescript involves adding `@types/omelette` too, and it's got some wrong typings at time of writing (fix for what I noticed here: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/72175)

I'd be willing to open a PR to convert coffee -> typescript, if it'd be welcome. Worth noting that it'd probably involve adding typescript as a dev dependency, and creating a `.gitignore` containing node_modules, etc. Also I am not v familiar with deno but I think lately it allows importing from `path`, `events` etc. directly without having to use `deno.land`.