feat(pisicine-go): add README.md for new exercise shoppinglistsort

subjects/shoppinglistsort/README.md

@@ -0,0 +1,37 @@
+# shoppinglistsort
+
+### Instructions
+
+You were sent to the supermarket with a shopping list. To make your shopping faster, write a function `ShoppingListSort()` that takes an array of strings and sorts it, according to the string length, returning an array in which the strings appear in ascending order.
+
+In the case of equal string length the order does not matter.
+
+### Expected function
+
+```go
+func ShoppingListSort(array[] string)[]string {
+
+}
+```
+
+### Usage
+
+Here is a possible program to test your function:
+
+```go
+package main
+
+import "fmt"
+
+func main() {
+	 array:= []string{"Banana", "Mushroom", "Salt", "Pepper","Tea", "Milk"}
+   fmt.Println(ShoppingListSort(array))
+}
+```
+
+And its output:
+
+```go
+$ go run . | cat -e
+[Tea Salt Milk Banana Pepper Mushroom]$
+```