Fix typo on storybook migration documents

[pruthvip15]

Closes #

What I did

Fixed a typo in the migration documents

How to test

Not required

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Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[jonniebigodes]

@pruthvip15, thanks for taking the time to put together this pull request and catch that important typo in our documentation. Appreciate it. I've checked and it's all good on my end.

Going to merge this.