Change export to default (#37558)

types/reach__alert/index.d.ts

@@ -7,7 +7,9 @@
 import * as React from 'react';
 
 export type AlertProps = {
-    type?: "assertive" | "polite";
+  type?: 'assertive' | 'polite';
 } & React.HTMLProps<HTMLDivElement>;
 
-export const Alert: React.FC<AlertProps>;
+declare const Alert: React.FC<AlertProps>;
+
+export default Alert;

types/reach__alert/reach__alert-tests.tsx

@@ -1,4 +1,4 @@
-import { Alert } from '@reach/alert';
+import Alert from '@reach/alert';
 
 import * as React from "react";
 import { render } from "react-dom";