Add example of concatenated interpolated strings

[SeanKilleen]

Summary

Adds a description of how to break up interpolated strings, based on feedback in #29440.

Fixes #29440.

[IEvangelist]

Looks good to me, we'll - thank you 🙏

[gewarren]

Why wouldn't this just be:

var combinedInterpolatedString = $"{firstWord}, {secondWord}!";

@BillWagner

[BillWagner]

That would work, but wouldn't show the example as concatenating two interpolated strings. Admittedly, in this case, a single interpolated string would be clear. This would normally be done when all the source expressions were more complex.

[SeanKilleen]

@gewarren it could be, for sure. I was using an example provided in the initial issue, which discussed concatenating multiple strings together specifically. So it may be that in the context of the example, the usefulness is lost.

Perhaps I could add something like "bear in mind, you could also accomplish this via" and use the syntax you've provided above?

[BillWagner]

@SeanKilleen I'd prefer a more involved example where two different interpolated strings are constructed, then concatenated.

[gewarren]

I agree with Bill here. I don't think this is a good example.

[gewarren]

I'd change this to:

To combine multiple interpolated strings, add the `$` special character to each string literal.