Documentation/website: Single page cheatsheet

[Raynos]

The type system for python has a nice cheatsheet ( https://mypy.readthedocs.io/en/latest/cheat_sheet.html ).

I've copied this in the past ( https://github.com/Raynos/jsig/blob/master/docs/cheatsheet.md ).

Such a cheatsheet is a great feature for the website

• Shows a list of types available
• Shows the behavior of type inference with no annotations
• Shows examples of adding type annotations
• Shows examples of refinement
• Shows example of casting syntax
• Shows examples of debugging ( reveal_type / typeof x;
• Shows examples of common places where a type annotation is needed and a user might "expect" inference to just work, e.g. const x = [] etc

It's an easy to share link that gives a quick refresher on how to use Hegel.

[JSMonk]

Oh, nice. I will add it to Hegel. Thank you a lot for the suggestion ^_^