Add "Media" tab for rooms (#196)

* WIP on Media tab to rooms

* handle error for downloadFile if it's missing

* Add warning message for rooms Media tab

* Fix error message for download media of rooms

* update readme

src/pages/LoginPage.tsx

@@ -16,7 +16,7 @@ import {
 } from "react-admin";
 import { useFormContext } from "react-hook-form";
 import LoginFormBox from "../components/LoginFormBox";
-import { useAppContext } from "../App";
+import { useAppContext } from "../Context";
 import {
   getServerVersion,
   getSupportedFeatures,