docs: list supported values for read in decorator metadata (#42370)

fixes #20927

PR Close #42370

packages/core/src/metadata/di.ts

@@ -154,6 +154,13 @@ export interface ContentChildrenDecorator {
    *   removed in future versions of Angular.
    * * **read** - Used to read a different token from the queried elements.
    *
+   * The following values are supported by `read`:
+   *   * Any class with the `@Component` or `@Directive` decorator
+   *   * Any provider defined on the injector of the component that is matched by the `selector` of
+   * this query
+   *   * Any provider defined through a string token (e.g. `{provide: 'token', useValue: 'val'}`)
+   *   * `TemplateRef`, `ElementRef`, and `ViewContainerRef`
+   *
    * @usageNotes
    *
    * Here is a simple demonstration of how the `ContentChildren` decorator can be used.
@@ -230,6 +237,13 @@ export interface ContentChildDecorator {
    * * **static** - True to resolve query results before change detection runs,
    * false to resolve after change detection. Defaults to false.
    *
+   * The following values are supported by `read`:
+   *   * Any class with the `@Component` or `@Directive` decorator
+   *   * Any provider defined on the injector of the component that is matched by the `selector` of
+   * this query
+   *   * Any provider defined through a string token (e.g. `{provide: 'token', useValue: 'val'}`)
+   *   * `TemplateRef`, `ElementRef`, and `ViewContainerRef`
+   *
    * @usageNotes
    *
    * {@example core/di/ts/contentChild/content_child_howto.ts region='HowTo'}
@@ -293,6 +307,13 @@ export interface ViewChildrenDecorator {
    *   ** Note: *** This config option is **deprecated**, it will be permanently set to `true` and
    * removed in future versions of Angular.
    *
+   * The following values are supported by `read`:
+   *   * Any class with the `@Component` or `@Directive` decorator
+   *   * Any provider defined on the injector of the component that is matched by the `selector` of
+   * this query
+   *   * Any provider defined through a string token (e.g. `{provide: 'token', useValue: 'val'}`)
+   *   * `TemplateRef`, `ElementRef`, and `ViewContainerRef`
+   *
    * @usageNotes
    *
    * {@example core/di/ts/viewChildren/view_children_howto.ts region='HowTo'}
@@ -368,6 +389,13 @@ export interface ViewChildDecorator {
    *   * A `TemplateRef` (e.g. query `<ng-template></ng-template>` with `@ViewChild(TemplateRef)
    * template;`)
    *
+   * The following values are supported by `read`:
+   *   * Any class with the `@Component` or `@Directive` decorator
+   *   * Any provider defined on the injector of the component that is matched by the `selector` of
+   * this query
+   *   * Any provider defined through a string token (e.g. `{provide: 'token', useValue: 'val'}`)
+   *   * `TemplateRef`, `ElementRef`, and `ViewContainerRef`
+   *
    * @usageNotes
    *
    * {@example core/di/ts/viewChild/view_child_example.ts region='Component'}