Add formatting for CA2247 example

[kurnakovv]

Summary

https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca2247

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Internal previews

📄 File	🔗 Preview link
docs/fundamentals/code-analysis/quality-rules/ca2247.md	CA2247: Argument passed to TaskCompletionSource constructor should be TaskCreationOptions enum instead of TaskContinuationOptions enum