Fix documentation for `@macro` and reflection types

Since `@macro` doesn't exist anymore and these reflections are no longer AssociationReflections but their own types of reflections based on their macros (HasManyReflection, HasOneReflection etc) I updated the documentation to match the changes I made in #16089 and #16198.

An `AssociationReflection` that had a `@macro` of `:has_many` now is a `HasManyReflection`.