docs: clarify gzip_buffers unit size (apache#11526)

Author: kayx23

docs/en/latest/plugins/gzip.md

@@ -46,8 +46,8 @@ This Plugin requires APISIX to run on [APISIX-Runtime](../FAQ.md#how-do-i-build-
 | min_length     | integer              | False    | 20            | >= 1         | Dynamically sets the `gzip_min_length` directive.                                       |
 | comp_level     | integer              | False    | 1             | [1, 9]       | Dynamically sets the `gzip_comp_level` directive.                                       |
 | http_version   | number               | False    | 1.1           | 1.1, 1.0     | Dynamically sets the `gzip_http_version` directive.                                     |
-| buffers.number | integer              | False    | 32            | >= 1         | Dynamically sets the `gzip_buffers` directive.                                          |
-| buffers.size   | integer              | False    | 4096          | >= 1         | Dynamically sets the `gzip_buffers` directive.                                          |
+| buffers.number | integer              | False    | 32            | >= 1         | Dynamically sets the `gzip_buffers` directive parameter `number`.                                          |
+| buffers.size   | integer              | False    | 4096          | >= 1         | Dynamically sets the `gzip_buffers` directive parameter `size`. The unit is in bytes.                                          |
 | vary           | boolean              | False    | false         |              | Dynamically sets the `gzip_vary` directive.                                             |
 
 ## Enable Plugin

docs/zh/latest/plugins/gzip.md

@@ -46,8 +46,8 @@ description: 本文介绍了关于 Apache APISIX `gzip` 插件的基本信息及
 | min_length     | integer              | 否      |  20            | >= 1     | 动态设置 [`gzip_min_length`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_min_length) 指令。                      |
 | comp_level     | integer              | 否      |  1             | [1, 9]   | 动态设置 [`gzip_comp_level`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_comp_level) 指令。                      |
 | http_version   | number               | 否      |  1.1           | 1.1, 1.0 | 动态设置 [`gzip_http_version`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_http_version) 指令。                  |
-| buffers.number | integer              | 否      |  32            | >= 1     | 动态设置 [`gzip_buffers`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_buffers) 指令。                            |
-| buffers.size   | integer              | 否      |  4096          | >= 1     | 动态设置 [`gzip_buffers`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_buffers) 指令。                            |
+| buffers.number | integer              | 否      |  32            | >= 1     | 动态设置 [`gzip_buffers`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_buffers) 指令 参数 `number`。                            |
+| buffers.size   | integer              | 否      |  4096          | >= 1     | 动态设置 [`gzip_buffers`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_buffers) 指令参数 `size`。单位为字节。                            |
 | vary           | boolean              | 否      |  false         |          | 动态设置 [`gzip_vary`](https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_vary) 指令。                                  |
 
 ## 启用插件