Added documentation for ax.utils.common.deprecation module to addre…

…ss GitHub Actions Test Failure (#2700)

Summary:
Pull Request resolved: #2700

This addresses T199733564 by adding missing documentation for the `ax.utils.common.deprecation` module introduced in D61601511.

Reviewed By: bernardbeckerman

Differential Revision: D61727254

fbshipit-source-id: 955c289850da11775c3163b232d125f802f6f284

sphinx/source/utils.rst

@@ -35,6 +35,14 @@ Decorator
     :undoc-members:
     :show-inheritance:
 
+Deprecation
+~~~~~~~~~~~
+
+.. automodule:: ax.utils.common.deprecation
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 Docutils
 ~~~~~~~~