fix broken link

Author: bytestream

_entries/required-method.md

@@ -27,7 +27,7 @@ Makes the element required, depending on the result of the given expression.
 
 **dependency-expression** *(String)*
 
-An expression (String) that is evaluated in the context of the element's form, making the field required only if the expression returns more than one element. Very often your expression will use selector filters such as `#foo:checked`, `#foo:filled`, `#foo:visible`. This plugin provides [custom selectors for that purpose](/category/selectors/).
+An expression (String) that is evaluated in the context of the element's form, making the field required only if the expression returns more than one element. Very often your expression will use selector filters such as `#foo:checked`, `#foo:filled`, `#foo:visible`. This plugin provides [custom selectors for that purpose](/documentation#custom-selectors).
 
 ### Form 3