Add a release note entry about .pyi support

Author: mdboom

cuda_core/docs/source/release/1.1.0-notes.rst

@@ -56,6 +56,10 @@ New features
   inspecting or augmenting a captured graph, or populating a conditional
   body entirely through the explicit API.
 
+- ``cuda.core`` now ships with ``.pyi`` stubs for all public APIs, enabling
+  users' IDEs and type checkers to provide better autocompletion and static
+  analysis.
+
 Bug fixes
 ---------