minor #15992 [Form] Minor deletion (ThomasLandauer)

This PR was merged into the 4.4 branch.

Discussion
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[Form] Minor deletion

Follow-up of #15982
The point is that it's included in **label** (not in *errors*) ;-)

About the syntax: Would it be possible to add a link to RST/Spinx to the "edit" `<textarea>` on GitHub?

Commits
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01bd2ce [Form] Minor deletion

Author: wouterj

form/form_customization.rst

@@ -267,8 +267,9 @@ Renders any errors for the given field.
 
 .. caution::
 
-    In the :ref:`error messages of Bootstrap 4 Form Theme <reference-forms-bootstrap4-error-messages>`,
-    ``form_errors()`` is already included in ``form_label()``.
+    In the Bootstrap 4 form theme, ``form_errors()`` is already included in
+    ``form_label()``. Read more about this in the
+    :ref:`Bootstrap 4 theme documentation <reference-forms-bootstrap4-error-messages>`.
 
 .. _reference-forms-twig-widget: