doc(macros): add missing using QuoteContext

[robstoll]

I tried to run the example with scastie: https://scastie.scala-lang.org/9xO9TXZKS8ydfLsSo3ZJ0g
I guess the example is missing the using QuoteContext.
Where do I get this context from initially?

[nicolasstucki]

Each ${ } provides a given QuoteContext within it. Usually it re-provides the QuoteContext that it's surrounding '{ } uses. In particular, in a macro the first QuoteContext is provided within the ${ } which is instantiated by the compiler when expanding the macro. Alternatively, the first QuoteContext can also come from the scala.quoted.staging.run or scala.quoted.staging.withQuoteContext.

[robstoll]

Thank you very much for the explanation 🙂 👍