Add used-by-Python comments to top-level files
diff --git a/setup.cfg b/setup.cfg
index 52b6b50..add6ee8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,3 +1,5 @@
+# Setup settings for GRPC Python
+
 [coverage:run]
 plugins = Cython.Coverage