message: demo-protobuf: Wrap protobuf field decorator
diff: @@ -17,8 +17,12 @@ function CosmosMessage(registry: Registry, typeUrl: string): TypeDecorator<any>
  };
  }
  +const CosmosField = {
  + String: (id: number) => Field.d(id, "string"),
  +};
  +
  @CosmosMessage(myRegistry, "/demo.MsgDemo")
  export class MsgDemo extends Message<{}> {
  - @Field.d(1, "string")
  + @CosmosField.String(1)
  public readonly example: string = "";
  }
  