docs(forms): ngSubmit isn't an Angular directive.

public/docs/ts/latest/guide/forms.jade

@@ -575,7 +575,7 @@ figure.image-display
   trigger a form submit because of its type (`type="submit"`).
 
   A "form submit" is useless at the moment.
-  To make it useful, we'll update the `<form>` tag with another Angular directive, `NgSubmit`,
+  To make it useful, we'll update the `<form>` tag with another event property, `ngSubmit`,
   and bind it to the `HeroFormComponent.submit()` method with an  event binding
 +makeExample('forms/ts/app/hero-form.component.html', 'ngSubmit')(format=".")
 
@@ -671,7 +671,7 @@ figure.image-display
 
   - An Angular HTML form template.
   - A form component class with a `Component` decorator.
-  - The `ngSubmit` directive for handling the form submission.
+  - The `ngSubmit` property for handling the form submission.
   - Template reference variables such as `#heroForm`, `#name` and `#power`.
   - The `[(ngModel)]` syntax and a `name` attribute for two-way data binding, validation and change tracking.
   - The reference variable’s `valid` property on input controls to check if a control is valid and show/hide error messages.