Documentation: Clarifies how to assign a template to a default Post Type

docs/templates.md

@@ -68,3 +68,17 @@ Sometimes the intention might be to lock the template on the UI so that the bloc
 
 - `all` — prevents all operations.
 - `insert` — prevents inserting new blocks, but allows moving existing ones.
+
+## Default Post Types
+
+It is also possible to assign a template to a default post type like "posts" and "pages":
+
+```php
+$post_type_object = get_post_type_object( 'post' );
+$post_type_object->template = array(
+	array( 'core/paragraph', array(
+		'placeholder' => 'Add Description...',
+	) ),
+);
+$post_type_object->template_lock = 'all';
+```