refine doc

Author: huangshuwei

examples/src/docs/en/theme.md

@@ -11,8 +11,6 @@ import blue theme style
 import "vue-easytable/libs/theme-default/index.css";
 ```
 
-example：
-
 #### Use Dark Theme
 
 import dark theme style
@@ -21,8 +19,6 @@ import dark theme style
 import "vue-easytable/libs/theme-dark/index.css";
 ```
 
-example：
-
 :::anchor Theme Custom
 
 The style of vue-easytable uses less as the development language,A series of global / component style variables are defined,You can adjust to your needs.

examples/src/docs/zh/theme.md

@@ -11,16 +11,12 @@
 import "vue-easytable/libs/theme-default/index.css";
 ```
 
-示例：
-
 #### 使用暗黑主题
 
 ```
 import "vue-easytable/libs/theme-dark/index.css";
 ```
 
-示例：
-
 :::anchor 主题定制
 
 vue-easytable 的样式使用了 Less 作为开发语言，并定义了一系列全局/组件的样式变量，你可以根据需求进行相应调整。