docs(forms): migrate @whatItDoes tags to the description (#23186)

We get the overview for the doc by splitting off the first
paragraph.

PR Close #23186

packages/forms/src/directives/ng_no_validate_directive.ts

@@ -9,7 +9,9 @@
 import {Directive} from '@angular/core';
 
 /**
- * @whatItDoes Adds `novalidate` attribute to all forms by default.
+ * @description
+ *
+ * Adds `novalidate` attribute to all forms by default.
  *
  * `novalidate` is used to disable browser's native form validation.
  *