fix docs

Author: sycai

docs/reference/bigframes.pandas/frame.rst

@@ -38,4 +38,7 @@ Struct handling
 AI operators
 ^^^^^^^^^^^^
 
-.. automethod:: bigframes.operations.ai.AIAccessor.forecast
+.. autoclass:: bigframes.operations.ai.AIAccessor
+    :members:
+    :inherited-members:
+    :undoc-members:

docs/templates/toc.yml

@@ -220,7 +220,6 @@
       uid: bigframes.bigquery
     - name: BigQuery AI Functions
       uid: bigframes.bigquery._operations.ai
-      status: beta
     name: bigframes.bigquery
   - items:
     - name: GeoSeries