[easy] missing Context

Pull Request resolved: #1452

this is to make it show up in docs.
ghstack-source-id: 314896718

Differential Revision: [D84080808](https://our.internmc.facebook.com/intern/diff/D84080808/)

**NOTE FOR REVIEWERS**: This PR has internal Meta-specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D84080808/)!

Author: zdevito

python/monarch/actor/__init__.py

@@ -18,6 +18,7 @@
     as_endpoint,
     Channel,
     context,
+    Context,
     current_actor_name,
     current_rank,
     current_size,
@@ -80,4 +81,5 @@
     "run_worker_loop_forever",
     "attach_to_workers",
     "enable_transport",
+    "Context",
 ]