docs(reversemenuindex): change the markdown instructions

subjects/reversemenuindex/README.md

@@ -4,7 +4,7 @@
 
 The restaurant employees are having a really tough day and are delivering the customers' food in the wrong order. You need to fix the problem so that they can deliver it correctly.
 
-Write a function `ReverseMenuIndex()` that takes an array of strings as arguments and returns another array of strings with the menu in the correct order.
+Write a function `ReverseMenuIndex()` that takes a `slice` of strings as an argument and returns another `slice` of strings with the menu in the correct order.
 
 - `append()` is not allowed for this exercise.
 
@@ -35,7 +35,7 @@ func main() {
 
 And its output:
 
-```go
+```console
 $ go run . | cat -e
 [starters drinks mains desserts]$
 ```