minor #18193 Adding more details on action and method (ThomasLandauer)

This PR was merged into the 5.4 branch.

Discussion
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Adding more details on `action` and `method`

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09d44cb Adding more details on `action` and `method`

Author: javiereguiluz

forms.rst

@@ -755,8 +755,9 @@ Set the ``label`` option on fields to define their labels explicitly::
 Changing the Action and HTTP Method
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-By default, a form will be submitted via an HTTP POST request to the same
-URL under which the form was rendered. When building the form in the controller,
+By default, the ``<form>`` tag will be rendered with a ``method="post"`` attribute,
+and no ``action`` attribute, causing it to be submitted via an HTTP POST request to the same
+URL under which it was rendered. When building the form,
 use the ``setAction()`` and ``setMethod()`` methods to change this::
 
     // src/Controller/TaskController.php