Also allows links to the builtins from autocomplete and signature help where documentation is available.

Using type stubs from microbit-foundation/micropython-microbit-stubs#101

To discuss:

• Maybe we should filter out API docs for builtin classes where we don't show any methods as they are filtered out as __new__
• Add some kind of indicator that not all classes, class methods and functions are documented in the builtins section

Notes from Matt:

• I've exempted __new__ but not convinced about exposing __new__ vs __init__ complexity to our users. But hard to mask it too... for str and list at least they do need to understand it as an object with methods.
• Very weird to see range() three times because of overloads that exist for invisible type-related reasons. Same applies to constructors.
• The base class names are likely too scary for our users
• Lots of useful functions that are worth adding if everyone's happy with the idea (e.g. min, max)

Unfortunate case where we are filtering out __new__ (with other special methods), but they are the only methods documented in the class:

- Examples for str, list
- Don't import "builtins" or fully qualify it