Initial experiments with resizing of room lists

res/css/views/rooms/_RoomList.scss

@@ -15,6 +15,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+.mx_RoomList2_resizer {
+    cursor: ns-resize;
+}
+
+.mx_RoomList.mx_RoomList2 {
+    overflow-y: auto;
+}
+
 .mx_RoomList {
     /* take up remaining space below TopLeftMenu */
     flex: 1;