Port source from CoffeeScript over to Civet

[Mokshit06]

Related to #45.

Moves coffeescript source over to Civet and adds type definitions. Haven't removed the CS source code yet, as @danielx/civet doesn't have the unplugin plugin exported yet in the latest released npm version, so we can't publish it.

We can remove that once the type definitions and type names have been finalised and the build system can support the compilation from civet -> js + dts