Adding TOC

Author: SnehaGunda

articles/synapse-analytics/toc.yml

@@ -1449,6 +1449,8 @@ items:
       href: ./spark/apache-spark-machine-learning-training.md
     - name: Deep learning 
       href: ./machine-learning/concept-deep-learning.md
+    - name:  SynapseML library
+      href: ./machine-learning/synapse-machine-learning-library.md
   - name: Tutorials
     items:
     - name: Data access and preparation