Update README.md spelling error, one letter.

[daylennguyen]

storybook/defaul-exports => storybook/default-exports

Issue: #

What Changed

Checklist

Check the ones applicable to your change:

• [ ] Ran yarn update-all
• [ ] Tests are updated
• [ ] Documentation is updated

Change Type

Indicate the type of change your pull request is:

• [ ] maintenance
• [x] documentation
• [ ] patch
• [ ] minor
• [ ] major

[yannbf]

Hey @daylennguyen thank you so much for your contribution. Great catch!

[github-actions[bot]]

:rocket: PR was released in v0.5.2 :rocket: