message: docs: expand input descriptions
  PR Close
diff: @@ -134,8 +134,21 @@ export class NgForOf<T> implements DoCheck {
  this._ngForOfDirty = true;
  }
  /**
  - * A function that customizes the default tracking algorithm.
  - * When supplied, Angular tracks changes by the return value of the function.
  + * A function that defines how to track changes for items in the iterable.
  + *
  + * When items are added, moved, or removed in the iterable,
  + * the directive must re-render the appropriate DOM nodes.
  + * To minimize churn in the DOM, only nodes that have changed
  + * are re-rendered.
  + *
  + * By default, the change detector assumes that
  + * the object instance identifies the node in the iterable.
  + * When this function is supplied, the directive uses
  + * the result of calling this function to identify the item node,
  + * rather than the identity of the object itself.
  + *
  + * The function receives two inputs,
  + * the iteration index and the node object ID.
  */
  @Input()
  set ngForTrackBy(fn: TrackByFunction<T>) {
  @@ -164,9 +177,8 @@ export class NgForOf<T> implements DoCheck {
  private _differs: IterableDiffers) {}
  /**
  - * The [template reference variable](guide/template-syntax#template-reference-variables--var-)
  - * for the expanded directive.
  - * Compare [template input variable](guide/structural-directives#template-input-variable)
  + * A reference to the template that is stamped out for each item in the iterable.
  + * @see [template reference variable](guide/template-syntax#template-reference-variables--var-)
  */
  @Input()
  set ngForTemplate(value: TemplateRef<NgForOfContext<T>>) {
  