minor #5784 Fix method names in example. (vlad-ghita)

This PR was merged into the 4.x branch.

Discussion
----------

Fix method names in example.

<!--
Thanks for your contribution! If you are proposing a new feature that is complex,
please open an issue first so we can discuss about it.

Note: all your contributions adhere implicitly to the MIT license
-->

Commits
-------

494e438 Fix method names in example.

doc/fields.rst

@@ -577,9 +577,9 @@ precise control, use the ``Asset`` class to define the assets::
     // ...
 
     TextField::new('firstName', 'Name')
-        ->addCssFiles(Asset::new('bundle/some-bundle/foo.css')->ignoreOnForms()->htmlAttr('media', 'print'))
+        ->addCssFiles(Asset::new('bundle/some-bundle/foo.css')->ignoreOnForm()->htmlAttr('media', 'print'))
         ->addJsFiles(Asset::new('admin/some-custom-code.js')->onlyOnIndex()->defer())
-        ->addWebpackEncoreEntry(Asset::new('admin-maps')->onlyWhenCreating()->preload())
+        ->addWebpackEncoreEntries(Asset::new('admin-maps')->onlyWhenCreating()->preload())
         // you can even define the Symfony Asset package which the asset belongs to
         ->addCssFiles(Asset::new('some-path/bar.css')->package('legacy_assets'))
     ;