Update app.py

app.py

@@ -56,3 +56,10 @@ st.sidebar.markdown("""
 - [Applications](#Applications-of-Machine-Learning)
 - [Conclusion](#Conclusion)
 """)
+# Nested sidebar for "Types of Machine Learning"
+with st.sidebar.expander("Types of Machine Learning"):
+    st.markdown("""
+    - [Supervised Learning](#Supervised-Learning)
+    - [Unsupervised Learning](#Unsupervised-Learning)
+    - [Reinforcement Learning](#Reinforcement-Learning)
+    """)