Fix ToC header

apps/article.py

@@ -4,8 +4,8 @@ from streamlit_tensorboard import st_tensorboard
 from .utils import Toc
 def app(state):
     toc = Toc()
-    st.title("Table of contents")
     st.info("Welcome to our Multilingual-VQA demo. Please use the navigation sidebar to move to our demo, or scroll below to read all about our project. 🤗")
+    st.header("Table of contents")
     toc.placeholder()
     toc.header("Introduction and Motivation")
     st.write(read_markdown("intro.md"))