Add basic types

src/components/structures/auth/Registration.tsx

@@ -1,5 +1,5 @@
 /*
-Copyright 2015, 2016, 2017, 2018, 2019, 2020 The Matrix.org Foundation C.I.C.
+Copyright 2015-2021 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -95,7 +95,7 @@ interface IState {
     // be seeing.
     serverIsAlive: boolean;
     serverErrorIsFatal: boolean;
-    serverDeadError: string;
+    serverDeadError?: ReactNode;
 
     // Our matrix client - part of state because we can't render the UI auth
     // component without it.