chore: reorganize the supported pandas apis page (#584)

Author: ashleyxuu

docs/templates/toc.yml

@@ -12,6 +12,8 @@
       name: Methods
     - href: summary_property.html
       name: Properties and Attributes
+    - href: supported_pandas_apis.html
+      name: Supported pandas APIs
     name: BigQuery DataFrames API
   - items:
     - items:
@@ -79,8 +81,6 @@
       name: Series
     - name: Window
       uid: bigframes.core.window.Window
-    - href: supported_pandas_apis.html
-      name: Supported pandas APIs
     name: bigframes.pandas
   - items:
     - items: