Make images in notes responsive

www/css/notecards.css

@@ -69,6 +69,10 @@ file, You can obtain one at http://mozilla.org/MPL/2.0/.
     margin-top: 0em;
 }
 
+.notecard .card-content img {
+    max-width: 100%;
+}
+
 .notecard {
     min-height: 4em;
 }