docs($compile): add 'templateNamespace' to example

Closes #9522

Author: Justin Walsh

src/ng/compile.js

@@ -61,6 +61,7 @@
  *       // templateUrl: 'directive.html', // or // function(tElement, tAttrs) { ... },
  *       transclude: false,
  *       restrict: 'A',
+ *       templateNamespace: 'html',
  *       scope: false,
  *       controller: function($scope, $element, $attrs, $transclude, otherInjectables) { ... },
  *       controllerAs: 'stringAlias',