➕ Chapter-2: Detect loop in SLL (careercup#7)

*  find middle node of a Singly Linked List

*  find middle node of a Singly Linked List

*  find middle node of a Singly Linked List

* add find-middle node tests

* Delete middle Node of Linked List

* correct2-3-Delete Middle Node

*  add solution for access to the head  / or access to middle-node

* 2-2: rturn Kth to Last

* add for loop for craating new node in  beforeEach for tests

* 2-8: Detection Loop in SLL

Author: Raziyehbazargan