docs(guide/filter): add link to list of built-in filters

Closes #14828

Author: lirantal

docs/content/guide/filter.ngdoc

@@ -5,10 +5,11 @@
 
 # Filters
 
-A filter formats the value of an expression for display to the user. They can be used in view templates,
-controllers or services and it is easy to define your own filter.
+Filters format the value of an expression for display to the user. They can be used in view
+templates, controllers or services. Angular comes with a collection of
+[built-in filters](api/ng/filter), but it is easy to define your own as well.
 
-The underlying API is the {@link ng.$filterProvider `filterProvider`}.
+The underlying API is the {@link ng.$filterProvider}.
 
 ## Using filters in view templates