Updated frontend/* articles to Symfony 4

Author: javiereguiluz

_build/redirection_map

@@ -351,6 +351,12 @@
 /event_dispatcher/class_extension /event_dispatcher
 /form /forms
 /form/use_virtual_forms /form/inherit_data_option
+/frontend/assetic/apply_to_option /frontend/assetic
+/frontend/assetic/asset_management /frontend/assetic
+/frontend/assetic/jpeg_optimize /frontend/assetic
+/frontend/assetic/php /frontend/assetic
+/frontend/assetic/uglifyjs /frontend/assetic
+/frontend/assetic/yuicompressor /frontend/assetic
 /security/target_path /security
 /service_container/third_party /service_container
 /templating/templating_service /templates

assetic/_standard_edition_warning.rst.inc

@@ -1,10 +1,8 @@
 Assetic
 =======
 
-.. include:: /assetic/_standard_edition_warning.rst.inc
+.. caution::
 
-.. toctree::
-    :maxdepth: 1
-    :glob:
-
-    assetic/*
+    Using Assetic to manage web assets in Symfony applications is no longer
+    recommended. Instead, use :doc:`Webpack Encore </frontend>`, which bridges
+    Symfony apps with modern JavaScript-based tools to manage web assets.