fix: .knowledgebase folder can be deleted bug and change "Add file to knowledge base" to "Link file to knowledge base" bug (#786)

### What problem does this PR solve?
fix: .knowledgebase folder can be deleted bug 
fix: change "Add file to knowledge base" to "Link file to knowledge
base" bug
#783 #784

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/locales/zh.ts

@@ -475,7 +475,7 @@ export default {
       knowledgeBase: '知识库',
       size: '大小',
       action: '操作',
-      addToKnowledge: '添加到知识库',
+      addToKnowledge: '链接知识库',
       pleaseSelect: '请选择',
       newFolder: '新建文件夹',
       uploadFile: '上传文件',