related to #1693 changed smarty version to 4.1.0

include/smarty/docs/programmers/api-variables/variable-php-handling.md

@@ -0,0 +1,21 @@
+\$php\_handling {#variable.php.handling}
+===============
+
+This tells Smarty how to handle PHP code embedded in the templates.
+There are four possible settings, the default being
+`Smarty::PHP_PASSTHRU`. Note that this does NOT affect php code within
+[`{php}{/php}`](#language.function.php) tags in the template.
+
+-   `Smarty::PHP_PASSTHRU` - Smarty echos tags as-is.
+
+-   `Smarty::PHP_QUOTE` - Smarty quotes the tags as html entities.
+
+-   `Smarty::PHP_REMOVE` - Smarty removes the tags from the templates.
+
+-   `Smarty::PHP_ALLOW` - Smarty will execute the tags as PHP code.
+
+> **Note**
+>
+> Embedding PHP code into templates is highly discouraged. Use [custom
+> functions](#plugins.functions) or [modifiers](#plugins.modifiers)
+> instead.