fixes to docs

docs/programmers/plugins/plugins-block-functions.md

@@ -62,7 +62,7 @@ cannot have both custom function `{func}` and block function
 
 If you have nested block functions, it\'s possible to find out what the
 parent block function is by accessing `$smarty->_tag_stack` variable.
-Just do a [`var_dump()`](&url.php-manual;var_dump) on it and the
+Just do a [`var_dump()`](https://www.php.net/var_dump) on it and the
 structure should be apparent.
 
 

docs/programmers/plugins/plugins-modifiers.md

@@ -25,7 +25,7 @@ The first parameter to the modifier plugin is the value on which the
 modifier is to operate. The rest of the parameters are optional,
 depending on what kind of operation is to be performed.
 
-The modifier has to [return](&url.php-manual;return) the result of its
+The modifier has to [return](https://www.php.net/return) the result of its
 processing.
 
 This plugin basically aliases one of the built-in PHP functions. It does

docs/programmers/plugins/plugins-naming-conventions.md

@@ -32,7 +32,7 @@ in order to be located by Smarty.
 
 -   And `name` should be a valid identifier; letters, numbers, and
     underscores only, see [php
-    variables](&url.php-manual;language.variables).
+    variables](https://www.php.net/language.variables).
 
 -   Some examples: `function.html_select_date.php`, `resource.db.php`,
     `modifier.spacify.php`.