Added session materials to gitbook sidebar

Author: adamblanchard

SUMMARY.md

@@ -116,10 +116,21 @@
       - [Assignment](courses/backend/databases/week2/assignment.md)
   - [Node](courses/backend/node/README.md)
     - [Week 1](courses/backend/node/week1/README.md)
+      - [Session Materials](courses/backend/node/week1/session-materials/)
+        - [1. Server](courses/backend/node/week1/session-materials/01-server.md)
+        - [2. Schema](courses/backend/node/week1/session-materials/02-schema.md)
+        - [3. Routing](courses/backend/node/week1/session-materials/03-routing.md)
+        - [4. Database connection](courses/backend/node/week1/session-materials/04-database-connection.md)
+        - [5. GET endpoints](courses/backend/node/week1/session-materials/05-get-endpoints.md)
+        - [6. Auth](courses/backend/node/week1/session-materials/06-auth.md)
       - [Preparation](courses/backend/node/week1/preparation.md)
       - [Session Plan](courses/backend/node/week1/session-plan.md)
       - [Assignment](courses/backend/node/week1/assignment.md)
     - [Week 2](courses/backend/node/week2/README.md)
+      - [Session Materials](courses/backend/node/week2/session-materials/)
+        - [7. POST endpoints](courses/backend/node/week2/session-materials/07-post-endpoint.md)
+        - [8. PUT endpoints](courses/backend/node/week2/session-materials/08-put-endpoint.md)
+        - [9. DELETE endpoints](courses/backend/node/week2/session-materials/09-delete-endpoint.md)
       - [Preparation](courses/backend/node/week2/preparation.md)
       - [Session Plan](courses/backend/node/week2/session-plan.md)
       - [Assignment](courses/backend/node/week2/assignment.md)