Add copilot use case examples

[anandmeg]

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Internal previews

📄 File	🔗 Preview link
docs/csharp/how-to/parse-strings-using-split.md	docs/csharp/how-to/parse-strings-using-split
docs/csharp/programming-guide/types/how-to-convert-a-string-to-a-number.md	docs/csharp/programming-guide/types/how-to-convert-a-string-to-a-number

[BillWagner]

Hi @anandmeg

overall, this is great. Can you move the two image files to a subfolder of this article? Thanks.

Once that's done, I'll

[BillWagner]

Thanks @anandmeg

Approved, and I'll when the build finishes.