Cleaned up API KEY placeholder text

[connortreacy]

What does this PR do?

Replaces placeholder text on API keys with a more generic string.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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  Pull Request section?
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• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

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