Add margin to shell in editor mode to avoid mis-selecting between scrollbar and drag handle

Author: wwwillchen

mesop/web/src/editor/editor.scss

@@ -40,3 +40,7 @@
     0 2px 2px #00000024,
     0 1px 5px #0000001f;
 }
+
+mesop-shell {
+  margin-right: 6px;
+}