integrate FileModel with ChatModel

src/Model/fileModel.ts

@@ -1,6 +1,15 @@
 // this file is responsible for managing files within chats.
 
-export default class FileModel {}
+import ChatModel from "./chatModel";
+
+export default class FileModel {
+  chatModel: ChatModel;
+
+  // init
+  constructor(chatModel: ChatModel) {
+    this.chatModel = chatModel;
+  }
+}
 
 // types
 export interface File {