Merge branch '5.3' into 5.4

* 5.3:
  [Testing] Add comments to the work-in-progress section

Author: javiereguiluz

.doctor-rst.yaml

@@ -106,3 +106,4 @@ whitelist:
         - 'End to End Tests (E2E)'
         - '.. code-block:: php'
         - '.. _`a feature to test applications using Mercure`: https://github.com/symfony/panther#creating-isolated-browsers-to-test-apps-using-mercure-or-websocket'
+        - '..  End to End Tests (E2E)'

testing.rst

@@ -1011,12 +1011,11 @@ Mailer Assertions
     <jane@example.com>`` into ``jane@example.com``.
 
 .. TODO
-    End to End Tests (E2E)
-    ----------------------
-
-    * panther
-    * testing javascript
-    * UX or form collections as example?
+..  End to End Tests (E2E)
+..  ----------------------
+..  * panther
+..  * testing javascript
+..  * UX or form collections as example?
 
 Learn more
 ----------