Fix scanpy link in API tutorial (#128)

Author: martinkim0

api_overview.ipynb

@@ -113,12 +113,13 @@
             ]
         },
         {
+            "attachments": {},
             "cell_type": "markdown",
             "metadata": {
                 "id": "USVZNzYFqWby"
             },
             "source": [
-                "Now we preprocess the data to remove, for example, genes that are very lowly expressed and other outliers. For these tasks we prefer the [Scanpy preprocessing module](https://scanpy.readthedocs.io/en/stable/api/index.html#module-scanpy.pp)."
+                "Now we preprocess the data to remove, for example, genes that are very lowly expressed and other outliers. For these tasks we prefer the [Scanpy preprocessing module](https://scanpy.readthedocs.io/en/stable/api.html#module-scanpy.pp)."
             ]
         },
         {