docs(filter): improve syntax for usage in templates

src/ng/filter.js

@@ -69,7 +69,7 @@
  *
  * The general syntax in templates is as follows:
  *
- *         {{ expression | [ filter_name ] }}
+ *         {{ expression [| filter_name[:parameter_value] ... ] }}
  *
  * @param {String} name Name of the filter function to retrieve
  * @return {Function} the filter function