Add form for transaction input.

clj/clarity/clarity/server.clj

        :headers {"Content-Type" "text/html"}
        :body (html [:form#query {:action "/facts" :accept-charset "utf-8"}
                     [:textarea {:name "q" :cols 80 :rows 20}]
                     [:input {:type "submit"alue "query"}]])})
                     [:input {:type "submit" :value "query"alue "query"}]]
                    [:form#facts {:action "/facts" :method "post"}
                     [:textarea {:name "facts" :cols 80 :rows 20}]
                     [:input {:type "submit" :value "transact!"}]])})
  (GET "/facts" {{query :q} :params}
       (pr-str (d/q (edn/read-string query) (d/db conn))))
  (POST "/facts" [facts]