feat(piscine-go): add README.md for new go exercise reversemenuindex

subjects/reversemenuindex/README.md

@@ -0,0 +1,38 @@
+## reversemenuindex
+
+### Instructions
+
+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.
+
+- `append` is not allowed for this exercise.
+
+### Expected function
+
+```go
+func ReverseMenuIndex(menu []string) []string {
+
+}
+```
+
+### Usage
+
+Here is a possible program to test your function:
+
+```go
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Println(ReverseMenuIndex([]string{"desserts", "mains", "drinks", "starters"}))
+}
+```
+
+And its output:
+
+```go
+$ go run . | cat -e
+[starters drinks mains desserts]$
+```