Update explainer.md

Author: youennf

explainer.md

@@ -114,7 +114,7 @@ of an encoded frame and adds 4 bytes of padding.
 
   // Receiver transform
   function createReceiverTransform() {
-    return  new TransformStream({
+    return new TransformStream({
       start() {},
       flush() {},
       async transform(encodedFrame, controller) {
@@ -313,4 +313,3 @@ in how the processing elements could be implemented.
 
 
 
-