docs: display all less variables (#7604)

src/slider/README.md

@@ -171,3 +171,19 @@ export default {
 | Name   | Description   |
 | ------ | ------------- |
 | button | Custom button |
+
+### Less Variables
+
+How to use: [Custom Theme](#/en-US/theme).
+
+| Name | Default Value | Description |
+| --- | --- | --- |
+| @slider-active-background-color | `@blue` | - |
+| @slider-inactive-background-color | `@gray-3` | - |
+| @slider-disabled-opacity | `@disabled-opacity` | - |
+| @slider-bar-height | `2px` | - |
+| @slider-button-width | `24px` | - |
+| @slider-button-height | `24px` | - |
+| @slider-button-border-radius | `50%` | - |
+| @slider-button-background-color | `@white` | - |
+| @slider-button-box-shadow | `0 1px 2px rgba(0, 0, 0, 0.5)` | - |

src/slider/README.zh-CN.md

@@ -177,3 +177,19 @@ export default {
 | 名称   | 说明           |
 | ------ | -------------- |
 | button | 自定义滑动按钮 |
+
+### 样式变量
+
+组件提供了下列 Less 变量，可用于自定义样式，使用方法请参考[主题定制](#/zh-CN/theme)。
+
+| 名称                              | 默认值                         | 描述 |
+| --------------------------------- | ------------------------------ | ---- |
+| @slider-active-background-color   | `@blue`                        | -    |
+| @slider-inactive-background-color | `@gray-3`                      | -    |
+| @slider-disabled-opacity          | `@disabled-opacity`            | -    |
+| @slider-bar-height                | `2px`                          | -    |
+| @slider-button-width              | `24px`                         | -    |
+| @slider-button-height             | `24px`                         | -    |
+| @slider-button-border-radius      | `50%`                          | -    |
+| @slider-button-background-color   | `@white`                       | -    |
+| @slider-button-box-shadow         | `0 1px 2px rgba(0, 0, 0, 0.5)` | -    |