add some config samples
diff --git a/samples/foo/src/main/resources/application.yaml b/samples/foo/src/main/resources/application.yaml
index 2dfd7aa..b223a45 100644
--- a/samples/foo/src/main/resources/application.yaml
+++ b/samples/foo/src/main/resources/application.yaml
@@ -4,6 +4,7 @@
 
 infras:
   mvc:
+# 自定义error输出的例子
     custom-error:
       enabled: true
       error-map:
@@ -15,6 +16,10 @@
       include-path: true
       include-timestamp: true
       include-status: true
-logging:
-  level:
-    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod: trace
+
+# 控制日志级别的例子
+#logging:
+#  level:
+#    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod: trace
+#    org.springframework.web.servlet.DispatcherServlet: debug
+