docs: add preview to components documentation

src/components/dyne-button/dyne-button.mdx

@@ -1,4 +1,4 @@
-import { Canvas, Controls, Meta, Stories } from '@storybook/blocks';
+import { Canvas, Controls, Meta, Primary, Stories } from '@storybook/blocks';
 
 import * as DyneButton from './dyne-button.stories';
 
@@ -26,6 +26,8 @@ The component comes in different variants such as `primary`, `secondary`, `large
 
 Button has the following properties:
 
+<Primary />
+
 <Controls />
 
 <Stories />