add QR code display

css/base.css

@@ -1203,7 +1203,7 @@ img.channel {
   flex-grow: 0;
   padding: 0.5rem 0.75rem;
   line-height: 1.5;
-  overflow-x: hidden;
+  overflow-x: clip;
 }
 
 /* Make sure padding is only applied at the top level panel */
@@ -1410,6 +1410,11 @@ img.channel {
   vertical-align: top;
 }
 
+/* Div holding QR code */
+.qr-code {
+  align-self: center;
+}
+
 /* Scrollable panel where the messages are shown */
 #messages-panel {
   position: relative;