docs(stateFilters): adds docs for state filters

Author: 0x-r4bbit

src/stateFilters.js

@@ -1,10 +1,28 @@
+/**
+ * @ngdoc filter
+ * @name ui.router.state.filter:isState
+ *
+ * @requires ui.router.state.$state
+ *
+ * @description
+ * Translates to {@link ui.router.state.$state#is $state.is("stateName")}.
+ */
 $IsStateFilter.$inject = ['$state'];
 function $IsStateFilter($state) {
   return function(state) {
     return $state.is(state);
   };
 }
 
+/**
+ * @ngdoc filter
+ * @name ui.router.state.filter:includeByState
+ *
+ * @requires ui.router.state.$state
+ *
+ * @description
+ * Translates to {@link ui.router.state.$state#includes $state.includes()}.
+ */
 $IncludedByStateFilter.$inject = ['$state'];
 function $IncludedByStateFilter($state) {
   return function(state) {