docs: removed mention about ServiceMiddleware (#936)

examples/addsvc/pkg/addservice/middleware.go

@@ -11,7 +11,7 @@ import (
 type Middleware func(Service) Service
 
 // LoggingMiddleware takes a logger as a dependency
-// and returns a ServiceMiddleware.
+// and returns a service Middleware.
 func LoggingMiddleware(logger log.Logger) Middleware {
 	return func(next Service) Service {
 		return loggingMiddleware{logger, next}