Improve clarity and grammar in Auto Classes documentation

[himani27301]

Improved wording and grammar in the Auto Classes documentation to enhance readability without changing functionality.

What does this PR do?

Fixes # (issue)

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

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[stevhliu]

thanks!

[stevhliu]

Suggested change

	Each auto class provides a method that allows it to be extended with custom classes.For example, if you define a custom model class `NewModel`, ensure that you also define a corresponding `NewModelConfig`. You can then register them with the auto classes as shown below:
	Each auto class provides a method that allows it to be extended with custom classes. For example, if you define a custom model class `NewModel`, ensure that you also define a corresponding `NewModelConfig`. You can then register them with the auto classes as shown below: