feat(list): standard library example

ds/list/list_test.go

@@ -0,0 +1,22 @@
+package list_test
+
+import (
+	"container/list"
+	"fmt"
+)
+
+// ExampleList is the provided example from the standard library container/list package.
+// https://pkg.go.dev/container/list
+func Example_standardLibraryList() {
+	// Create a new list and put some numbers in it.
+	l := list.New()
+	e4 := l.PushBack(4)
+	e1 := l.PushFront(1)
+	l.InsertBefore(3, e4)
+	l.InsertAfter(2, e1)
+
+	// Iterate through list and print its contents.
+	for e := l.Front(); e != nil; e = e.Next() {
+		fmt.Println(e.Value)
+	}
+}