add withAuth to exports (#20)

Author: nicknisi

src/index.ts

@@ -1,4 +1,4 @@
-import { getSignInUrl, getSignUpUrl, signOut, switchToOrganization } from './auth.js';
+import { getSignInUrl, getSignUpUrl, signOut, switchToOrganization, withAuth } from './auth.js';
 import { authLoader } from './authkit-callback-route.js';
 import { configure, getConfig } from './config.js';
 import { authkitLoader, refreshSession } from './session.js';
@@ -8,6 +8,7 @@ export {
   authLoader,
   authkitLoader,
   configure,
+  withAuth,
   getConfig,
   getSignInUrl,
   getSignUpUrl,