Add support for jt i18n function for use in JSX

.babelrc

@@ -18,7 +18,7 @@
           "extract": {
             "output": "locales/metabase-frontend.pot"
           },
-          "discover": ["t"]
+          "discover": ["t", "jt"]
         }]
       ]
     }

frontend/src/metabase/app.js

@@ -4,8 +4,9 @@ import 'babel-polyfill';
 import 'number-to-locale-string';
 
 // make the i18n function "t" global so we don't have to import it in basically every file
-import { t } from "c-3po";
+import { t, jt } from "c-3po";
 global.t = t;
+global.jt = jt;
 
 // set the locale before loading anything else
 import { setLocalization } from "metabase/lib/i18n";