chore(docs): adding docs to core.ts and annotations.ts

modules/angular2/src/render/api.ts

@@ -306,8 +306,22 @@ export class RenderCompiler {
   compile(view: ViewDefinition): Promise<ProtoViewDto> { return null; }
 }
 
+/**
+ * Abstract reference to the element which can be marshaled across web-worker boundry.
+ *
+ * This interface is used by the {@link Renderer} api.
+ */
 export interface RenderElementRef {
+  /**
+   * Reference to the {@link RenderViewRef} where the `RenderElementRef` is inside of.
+   */
   renderView: RenderViewRef;
+
+  /**
+   * Index of the element inside the {@link ViewRef}.
+   *
+   * This is used internally by the Angular framework to locate elements.
+   */
   boundElementIndex: number;
 }