Fix typos in ThrowArgumentException example

[DaZombieKiller]

What changes to the docs does this PR provide?

The example showcasing how to use the ThrowHelper API contains a typo: the code expects a return type of int where the current example uses ThrowArgumentException<string>. This PR fixes that minor typo.

PR Checklist

Please check if your PR fulfills the following requirements:

• Correctly picked the right branch to base the change off (dev for new features, master for typos/improvements)
• For new pages, used the provided template
• For new features, added an entry in the Table of Contents
• Ran against a spell and grammar checker
• Contains NO breaking changes

[opbld30]

Docs Build status updates of commit 18bb7ee:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/developer-tools/ThrowHelper.md	✅Succeeded	View

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