message: docs(core): indicate OnPush applies to children
  Indicate the OnPush change detection strategy applies to all child directives.
  Resolves confusion from
  PR Close
diff: @@ -18,6 +18,7 @@ export enum ChangeDetectionStrategy {
  * Use the `CheckOnce` strategy, meaning that automatic change detection is deactivated
  * until reactivated by setting the strategy to `Default` (`CheckAlways`).
  * Change detection can still be explicitly invoked.
  + * This strategy applies to all child directives and cannot be overridden.
  */
  OnPush = 0,
  