Add introductory qiskit in class module (#4103)

Co-authored-by: abbycross <across@us.ibm.com>

Author: kcmccormibm

learning/modules/quantum-mechanics/_toc.json

@@ -13,6 +13,10 @@
       "title": "Modules",
       "collapsible": false,
       "children": [
+	{
+          "title": "Get started with Qiskit in the classroom",
+          "url": "/learning/modules/quantum-mechanics/get-started-with-qiskit"
+        },
         {
           "title": "Superposition with Qiskit",
           "url": "/learning/modules/quantum-mechanics/superposition-with-qiskit"