docs: remove legacy demo link from readme (#1309)

CONTRIBUTING.md

@@ -40,7 +40,7 @@ cd univer
 npm i -g pnpm
 
 # install dependencies
-pnmp install
+pnpm install
 
 ```
 

README-ja.md

@@ -92,10 +92,9 @@ Univer にコードをコントリビュートしたい方は、コントリビ
 
 ## リンク
 
-- [ドキュメント](https://univer.ai/guides/introduction/) (現在は中国語版のみ)
+- [ドキュメント](https://univer.ai/ja-jp/guides/introduction/)
 - [Online Playground](https://univer.ai/playground/)
 - [公式 Website](https://univer.ai)
-- [レガシー Univer デモ](https://dream-num.github.io/univer-demo/)
 
 ### コミュニティ
 

README-zh.md

@@ -104,7 +104,6 @@ Univer 基于插件化架构设计，你可以安装以下包来增强 Univer 
 - [文档](https://univer.ai/guides/introduction/)
 - [在线 Playground](https://univer.ai/playground/)
 - [官方网站](https://univer.ai)
-- [Legacy Univer Demo](https://dream-num.github.io/univer-demo/)
 
 ### 社区
 

README.md

@@ -99,10 +99,9 @@ If you would like to contribute code to Univer, please refer to the contributing
 
 ## Links
 
-- [Documentation](https://univer.ai/guides/introduction/) (currently only Chinese version)
+- [Documentation](https://univer.ai/en-us/guides/introduction/)
 - [Online Playground](https://univer.ai/playground/)
 - [Official Website](https://univer.ai)
-- [Legacy Univer Demo](https://dream-num.github.io/univer-demo/)
 
 ### Community