docs: 修改水印导出名称 (#1855)

src/packages/__VUE/watermark/doc.en-US.md

@@ -8,12 +8,12 @@
 
 import { createApp } from 'vue';
 // vue
-import { Watermark } from '@nutui/nutui';
+import { WaterMark } from '@nutui/nutui';
 // taro
-import { Watermark } from '@nutui/nutui-taro';
+import { WaterMark } from '@nutui/nutui-taro';
 
 const app = createApp();
-app.use(Watermark);
+app.use(WaterMark);
 
 ```
 

src/packages/__VUE/watermark/doc.md

@@ -10,12 +10,12 @@
 
 import { createApp } from 'vue';
 // vue
-import { Watermark } from '@nutui/nutui';
+import { WaterMark } from '@nutui/nutui';
 // taro
-import { Watermark } from '@nutui/nutui-taro';
+import { WaterMark } from '@nutui/nutui-taro';
 
 const app = createApp();
-app.use(Watermark);
+app.use(WaterMark);
 
 ```