readme: update handler struct tags

README.md

@@ -372,8 +372,8 @@ param |    in    | only one |     cookie    | (position of param) request cookie
 param |   name   |    no    |   (e.g.`id`)   | specify request param`s name
 param | required |    no    |               | request param is required
 param |   desc   |    no    |   (e.g.`id`)   | request param description
-param |   len    |    no    | (e.g.`3:6` `3`) | length range of param's value
-param |   range  |    no    |  (e.g.`0:10`)  | numerical range of param's value
+param |   len    |    no    | (e.g.`3:6`) | length range [a,b] of param's value
+param |   range  |    no    |  (e.g.`0:10`)  | numerical range [a,b] of param's value
 param |  nonzero |    no    |               | param`s value can not be zero
 param |   maxmb  |    no    |   (e.g.`32`)   | when request Content-Type is multipart/form-data, the max memory for body.(multi-param, whichever is greater)
 param |  regexp  |    no    | (e.g.`^\\w+$`) | verify the value of the param with a regular expression(param value can not be null)

README_ZH.md

@@ -372,8 +372,8 @@ param |    in    | 有且只有一个 |     cookie    | （参数位置）请求
 param |   name   |      否      |     (如`id`)   | 自定义参数名
 param | required |      否      |   required    | 参数是否必须
 param |   desc   |      否      |     (如`id`)   | 参数描述
-param |   len    |      否      |   (如`3:6``3`)  | 字符串类型参数的长度范围
-param |   range  |      否      |   (如`0:10`)   | 数字类型参数的数值范围
+param |   len    |      否      |   (如`3:6`)  | 字符串类型参数的长度范围[a,b]
+param |   range  |      否      |   (如`0:10`)   | 数字类型参数的数值范围[a,b]
 param |  nonzero |      否      |    nonzero    | 是否能为零值
 param |   maxmb  |      否      |    (如`32`)    | 当前`Content-Type`为`multipart/form-data`时，允许使用的最大内存，当设置了多个时使用较大值
 param |  regexp  |      否      |   (如`^\w+$`)  | 使用正则验证参数值