Fixed explanation mistake in comment

src/error/option_unwrap/question_mark.md

@@ -8,7 +8,7 @@ function is being executed and return `None`.
 ```rust,editable
 fn next_birthday(current_age: Option<u8>) -> Option<String> {
 	// If `current_age` is `None`, this returns `None`.
-	// If `current_age` is `Some`, the inner `u8` gets assigned to `next_age`
+	// If `current_age` is `Some`, the inner `u8` + 1 gets assigned to `next_age`
     let next_age: u8 = current_age? + 1;
     Some(format!("Next year I will be {}", next_age))
 }