Support retrieving entities.

clj/clarity/clarity/server.clj

         (pr-str (d/q (edn/read-string query) (d/db conn)))
         (http-error 400 (pr-str {:error "Missing required `q` parameter"}))))
  (POST "/facts" [facts]
        (pr-str (d/transact conn (read-tx-data facts)))))
        (pr-str (d/transact conn (read-tx-data facts))))
  (GET "/entity/:id" [id]
       (pr-str (into {} (d/entity (d/db conn) (edn/read-string id))))))
(def app
  (-> app-routes