feat: add README file to traversal

linked_lists/README.md

@@ -0,0 +1,47 @@
+# linked list values
+
+Write a function, linked_list_values, that takes in the head of a linked list as an argument. The function should return a list containing all values of the nodes in the linked list.
+
+## test_00
+
+```
+a = Node("a")
+b = Node("b")
+c = Node("c")
+d = Node("d")
+
+a.next = b
+b.next = c
+c.next = d
+
+a -> b -> c -> d
+
+linked_list_values(a) # -> [ 'a', 'b', 'c', 'd' ]
+```
+
+## test_01
+
+```
+x = Node("x")
+y = Node("y")
+
+x.next = y
+
+# x -> y
+
+linked_list_values(x) # -> [ 'x', 'y' ]
+```
+
+## test_02
+
+```
+q = Node("q")
+
+# q
+
+linked_list_values(q) # -> [ 'q' ]
+```
+
+## test_03
+
+`linked_list_values(None) # -> [ ]`