Autoaliasattr: `TypeVar`

[JasonGrace2282]

Manim's autoaliasattr directive does not document TypeVars.
Especially as the amount of type hints in manim increase, this can make it confusing to read the type hint when occasions such as list[H] occur, when earlier in the code H was defined as TypeVar("H", bound=Hashable] and it was simply not documented.

Potentially, they could be a different section since they typically don't have a description associated with them, and, as such, several typevars can just be in one code block.
The more straightforward option is to just make them all classes, so that references work (similar to how it was done in #3484)