Change the menu button to a chevron

by design request

res/css/structures/_UserMenu.scss

@@ -16,7 +16,7 @@ limitations under the License.
 
 .mx_UserMenu {
 
-    // to make the ... button sort of aligned with the explore button below
+    // to make the menu button sort of aligned with the explore button below
     padding-right: 6px;
 
     .mx_UserMenu_headerButtons {
@@ -36,7 +36,7 @@ limitations under the License.
             mask-size: contain;
             mask-repeat: no-repeat;
             background: $primary-fg-color;
-            mask-image: url('$(res)/img/element-icons/context-menu.svg');
+            mask-image: url('$(res)/img/feather-customised/chevron-down.svg');
         }
     }