fix: update import path for Showcase component in CSV import plugin documentation (#2)

Author: jikkai

content/en-US/guides/sheets/tutorials/csv-import-plugin.mdx

@@ -1,5 +1,5 @@
 import { Callout } from 'nextra/components'
-import Showcase from '@univerjs-site/docs/showcase/sheets/csv-import-plugin'
+import Showcase from '@/showcase/sheets/csv-import-plugin'
 
 # How to write a CSV import plugin
 

content/zh-CN/guides/sheets/tutorials/csv-import-plugin.mdx

@@ -1,5 +1,5 @@
 import { Callout } from 'nextra/components'
-import Showcase from '@univerjs-site/docs/showcase/sheets/csv-import-plugin'
+import Showcase from '@/showcase/sheets/csv-import-plugin'
 
 # 编写一个 CSV 导入插件