Update README.md

Author: thesleuth

README.md

@@ -1,6 +1,6 @@
 # Data structures
 
-Fork this repository and submit your code via pull request.
+Fork this repository and submit the URL of your fork via the Student Portal.
 
 ## Linked List
 
@@ -28,3 +28,7 @@ Implement a singly linked list:
 - implement your linked list as a generic class that can store any type of object
 - Add a reverse method
 - Add a slice method that returns a copy of a subset of the element of the list (eg slice(2,8) returns a new linked list containing elements #2,3,4,5,6,7 -- but not 8)
+
+## Planning and Execution: 
+  * Rememember, **TESTS** for all of the methods involved should be written **BEFORE** their implemtations are written. 
+