Add announcement toast for 2.0

src/App.tsx

@@ -16,6 +16,7 @@ import { DatabaseProvider } from "./contexts/DatabaseContext";
 import { UserIdProvider } from "./contexts/UserIdContext";
 
 import { ToastProvider } from "./components/Toast";
+import { MigrationNotification } from "./MigrationNotification";
 
 function App() {
   return (
@@ -24,6 +25,7 @@ function App() {
         <AuthProvider>
           <KeyboardProvider>
             <ToastProvider>
+              <MigrationNotification />
               <Router>
                 <Switch>
                   {/* Legacy support camel case routes */}

src/MigrationNotification.tsx

@@ -0,0 +1,22 @@
+import { useEffect } from "react";
+import { useToasts } from "react-toast-notifications";
+import { Link } from "theme-ui";
+
+export function MigrationNotification() {
+  const { addToast } = useToasts();
+
+  useEffect(() => {
+    const message = (
+      <span>
+        The new era of Owlbear Rodeo is coming on July 19th. Make sure to
+        migrate your data before July 19th. <Link href="#">Read more</Link>
+      </span>
+    );
+    addToast(message, {
+      autoDismiss: false,
+      appearance: "info",
+    });
+  }, [addToast]);
+
+  return null;
+}