update doc string for CDP Commands

[mastrzyz]

Fixed spelling issue and fixed the return statement to be of Promise

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Motivation and Context

Types of changes

• [x ] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ x] I have read the contributing document.
• [x ] My change requires a change to the documentation.
• [ x] I have updated the documentation accordingly.
• [ x] I have added tests to cover my changes.
• [ x] All new and existing tests passed.

Fixed spelling issue and fixed the return statement to be of Promise

[CLAassistant]

All committers have signed the CLA.

[mastrzyz]

By the way, is there any current work to update the typing information for Selenium 4? I can try and add some of the v4 features into it.

[diemol]

Thank you, @mastrzyz! Congrats on your first contribution 🎉