reformatted playground and added averageWithArgs

averageWithArgs/averageWithArgs.go

@@ -0,0 +1,10 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func average2() {
+	fmt.Println(os.Args)
+}

averageWithArgs/go.mod

@@ -0,0 +1,3 @@
+module averageWithArgs
+
+go 1.21.3