feat: create story for subtitle

src/pages/ValidatorOnboarding/Deposit/DepositSubtitle.stories.ts

@@ -0,0 +1,19 @@
+import type { Meta, StoryObj } from '@storybook/react'
+
+import DepositSubtitle from './DepositSubtitle'
+
+const meta = {
+  title: 'ValidatorOnboarding/DepositSubtitle',
+  component: DepositSubtitle,
+  parameters: {
+    layout: 'centered',
+  },
+  tags: ['autodocs'],
+} satisfies Meta<typeof DepositSubtitle>
+
+export default meta
+type Story = StoryObj<typeof meta>
+
+export const Default: Story = {
+  args: {},
+}