feat: Added Backdrop story

Signed-off-by: Antonette Caldwell <[email protected]>

apps/design-system/src/stories/Backdrop.stories.tsx

@@ -0,0 +1,39 @@
+import type { Meta } from '@storybook/react';
+import { useState } from 'react';
+
+import { Backdrop, Button } from '@layer5/sistent-components';
+
+const meta = {
+  title: 'Example/Backdrop',
+  component: Backdrop,
+  parameters: {
+    layout: 'centered'
+  },
+  tags: ['autodocs']
+} satisfies Meta<typeof Backdrop>;
+
+export default meta;
+// type Story = StoryObj<typeof meta>;
+
+export function Basic() {
+  const [open, setOpen] = useState(false);
+  const handleClose = () => {
+    setOpen(false);
+  };
+  const handleOpen = () => {
+    setOpen(true);
+  };
+
+  return (
+    <div>
+      <Button onClick={handleOpen} variant="contained" label="Open Backdrop" />
+      <Backdrop
+        sx={{ color: '#fff', zIndex: (theme) => theme.zIndex.drawer + 1 }}
+        open={open}
+        onClick={handleClose}
+      >
+        Hello
+      </Backdrop>
+    </div>
+  );
+}