Introduction To State: Fix grammar mistake

[bigacz]

Because

There was a small grammar mistake.

This PR

• Fixes minor grammar mistake.

Issue

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[MaoShizhong]

Thanks for fixing the typo. While you're at it, would you mind appeasing the linter by rewording the first and last lesson overview items to be statements instead of questions?

e.g.

• What state in React is.
• What happens in React when state is changed.

[bigacz]

Sure thing, I think these changes are added now.