Docs should expose trimming attributes

[agocke]

Describe the issue or suggestion

When an API is marked with the RequiresUnreferencedCodeAttibute or RequiresDynamicCodeAttribute, that means it's incompatible with trimming or AOT, respectively.

This info is relevant to users of the API and should be visible somewhere in the docs.

Similarly, any type marked with [DynamicallyAccessedMembers] can impact users of the API. All of these attributes should be exposed in the API docs.