feat: add loading to ChatContainer and set font family to inter and add tooltip to Form.Item and download documents on the document list page (#136)

* feat: download documents on the document list page

* feat: add tooltip to Form.Item

* feat: set font family to inter

* feat: add loading to ChatContainer

web/typings.d.ts

@@ -1,4 +1,8 @@
 import 'umi/typings';
 declare module 'lodash';
 
-export type Nullable<T> = T | null;
+// declare type Nullable<T> = T | null; invalid
+
+declare global {
+  type Nullable<T> = T | null;
+}