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/en.ts

@@ -494,7 +494,7 @@ export default {
       knowledgeBase: 'Knowledge Base',
       size: 'Size',
       action: 'Action',
-      addToKnowledge: 'Add to Knowledge Base',
+      addToKnowledge: 'Link to Knowledge Base',
       pleaseSelect: 'Please select',
       newFolder: 'New Folder',
       file: 'File',

web/src/locales/zh-traditional.ts

@@ -458,7 +458,7 @@ export default {
       knowledgeBase: '知識庫',
       size: '大小',
       action: '操作',
-      addToKnowledge: '添加到知識庫',
+      addToKnowledge: '鏈接知識庫',
       pleaseSelect: '請選擇',
       newFolder: '新建文件夾',
       uploadFile: '上傳文件',

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',