RFC: Support improved schema discovery UX

[cdaringe]

Problem

I have wonderful fields on my schema, but I don't recall what the field names are. Consequently, i start typing "a... no that's not it. let's try 'b'! b... no no that's not it. c? ya! c expands to card--wonderful!"

Discussion

ideas:

• add jump-to support types
• inline in the hover context all child fields