macros.md: Documentation does not match example

It looks like the documentation was reflowed at some point, references to `t` are not present in this block, only in subsequent ones. If this is incorrect or if this section should be reflowed, please let me know and I'd be happy to do it.

Author: blast-hardcheese

docs/docs/reference/metaprogramming/macros.md

@@ -192,8 +192,8 @@ quote but no splice between the parameter binding of `T` and its
 usage. But the code can be rewritten by adding a binding of a `Type[T]` tag:
 
 ```scala
-def to[T, R](f: Expr[T] => Expr[R])(using Type[T], Type[R], Quotes): Expr[T => R] =
-   '{ (x: T) => ${ f('x) } }
+def to[T, R](f: Expr[T] => Expr[R])(using t: Type[T])(using Type[R], Quotes): Expr[T => R] =
+   '{ (x: $t) => ${ f('x) } }
 ```
 
 In this version of `to`, the type of `x` is now the result of