docs(elements): update api doc for custom elements (angular#38252)

by adding cross-references to Angular Elements Overview guide.

PR Close angular#38252

Author: jbogarthyde

packages/elements/src/create-custom-element.ts

@@ -18,6 +18,8 @@ import {createCustomEvent, getComponentInputs, getDefaultAttributeToPropertyInpu
  * that can be used for custom element registration. Implemented and returned
  * by the {@link createCustomElement createCustomElement() function}.
  *
+ * @see [Angular Elements Overview](guide/elements "Turning Angular components into custom elements")
+ *
  * @publicApi
  */
 export interface NgElementConstructor<P> {
@@ -115,6 +117,8 @@ export interface NgElementConfig {
  * static property to affect all newly created instances, or as a constructor argument for
  * one-off creations.
  *
+ * @see [Angular Elements Overview](guide/elements "Turning Angular components into custom elements")
+ *
  * @param component The component to transform.
  * @param config A configuration that provides initialization information to the created class.
  * @returns The custom-element construction class, which can be registered with