update / in config

Author: HumphreyYang

lectures/_config.yml

@@ -99,7 +99,7 @@ sphinx:
         - "https://intro.quantecon.org/"
         - null
       advanced:
-        - "https://python-advanced.quantecon.org"
+        - "https://python-advanced.quantecon.org/"
         - null
       jax:
         - "https://jax.quantecon.org/"