R1:bf50e0f87001

Compose and display method information in Diviner

Summary:
Ref T988. As mentioned elsewhere, one broad goal of this iteration is to reduce the amount of boilerplate documentation we need to write. For example:

- I want to set `@group` by default in most cases.
- I want to inherit things like `@param` and `@return` by default.
- I want to inherit method documentation by default.
- I want to inherit `@task` information.

This implements most of the method inheritance stuff.

This //looks// super…