Wrap long lines and add the versionadded directive

Author: javiereguiluz

components/form.rst

@@ -750,9 +750,17 @@ method to access the list of errors. It returns a
 Clearing Form Errors
 ~~~~~~~~~~~~~~~~~~~~
 
-Any errors can be manually cleared using the :method:`Symfony\\Component\\Form\\ClearableErrorsInterface::clearErrors` method. This is useful when you'd like to validate the form without showing validation errors to the user (i.e. during a partial AJAX submission or :doc:`dynamic form modification </form/dynamic_form_modification>`).
+.. versionadded:: 4.2
+    The ``clearErrors()`` method was introduced in Symfony 4.2.
 
-Because clearing the errors makes the form valid,  ``clearErrors()`` should only be called after testing whether the form is valid.
+Any errors can be manually cleared using the
+:method:`Symfony\\Component\\Form\\ClearableErrorsInterface::clearErrors`
+method. This is useful when you'd like to validate the form without showing
+validation errors to the user (i.e. during a partial AJAX submission or
+:doc:`dynamic form modification </form/dynamic_form_modification>`).
+
+Because clearing the errors makes the form valid, ``clearErrors()`` should only
+be called after testing whether the form is valid.
 
 Learn more
 ----------