Update doc references

Author: wch

shiny/session/_session.py

@@ -456,7 +456,7 @@ async def _handle_request(
                                 warnings.warn(
                                     "Unable to infer a filename for the "
                                     f"'{download_id}' download handler; please use "
-                                    "@session.download(filename=) to specify one "
+                                    "@render.download(filename=) to specify one "
                                     "manually",
                                     SessionWarning,
                                     stacklevel=2,

shiny/ui/_download_button.py

@@ -41,7 +41,7 @@ def download_button(
 
     See Also
     --------
-    ~shiny.Session.download
+    ~shiny.render.download
     ~shiny.ui.download_link
     """
 
@@ -96,7 +96,7 @@ def download_link(
 
     See Also
     --------
-    ~shiny.Session.download
+    ~shiny.render.download
     ~shiny.ui.download_link
     """