add immediate timeout for embed postMessage

pages/embed.js

@@ -78,6 +78,8 @@ class Embed extends React.Component {
   ref = React.createRef()
 
   postMessage = () => {
+    setTimeout(
+      () =>
         getParent(window).postMessage(
           JSON.stringify({
             // Used by embed provider
@@ -86,6 +88,8 @@ class Embed extends React.Component {
             height: this.ref.current.offsetHeight
           }),
           '*'
+        ),
+      0
     )
   }