Adds five use-case Knowledge Graph skills layered over /diffbot-dql:
diffbot-news, diffbot-organizations, diffbot-people, diffbot-places,
diffbot-deals. Ten skills total.

Routing is settled by row shape. All DQL verified against the live KG.
Pins diffbot-python>=0.2.1 so the documented CLI flags behave as written.
diffbot-people states that coverage is public online presence only.