add changelog for v0.19.1

Author: ysugimoto

CHANGELOG.md

@@ -1,8 +1,16 @@
 # CHANGELOG
 
+## v0.19.1
+
+Bugifxes
+
+- Fix Input message type generation for nested resolver [#33](https://github.com/ysugimoto/grpc-graphql-gateway/pull/33)
+
 ## v0.19.0
 
-- Fix Input message type generation [#31](https://github.com/ysugimoto/grpc-graphql-gateway/pull/31)
+Bugifxes
+
+- Fix Input message type generation [#32](https://github.com/ysugimoto/grpc-graphql-gateway/pull/32)
 - Fix Query argument field type [#30](https://github.com/ysugimoto/grpc-graphql-gateway/pull/30) (@tarunvelli)
 
 ## v0.18.1, v0.18.2