Add module names for the typedoc, make it work

Mark members with @private for typedoc.

tns-core-modules/text/formatted-string.d.ts

@@ -1,6 +1,9 @@
 /**
+ * @module "text/formatted-string"
+ * 
  * Contains the FormattedString and Span classes, which are used to create a formatted (rich text) strings.
- */
+ */ /** */
+
 import { Span } from "./span";
 import { ObservableArray } from "../data/observable-array";
 import { ViewBase } from "../ui/core/view";