Fix documentation for Multi.map method
The documentation for the `Multi.map` method is not correct. Specifically `This method is a shortcut for {@code multi.onItem().apply(mapper)}.` should be `This method is a shortcut for {@code multi.onItem().transform(mapper)}.`
@@ -341,7 +341,7 @@ public interface Multi<T> extends Publisher<T> {
* The function receives the received item as parameter, and can transform it. The returned object is sent
* downstream as {@code item} event.
* <p>
- * This method is a shortcut for {@code multi.onItem().apply(mapper)}.
+ * This method is a shortcut for {@code multi.onItem().transform(mapper)}.
*
* @param mapper the mapper function, must not be {@code null}
* @param <O> the type of item produced by the mapper function
