Include stack trace on startup errors in create app

Updated the backend index.ts in create-app to log the error as an object, rather than a string.
This causes the error to include a stack trace, along with the error message,
as well as bringing it in line with the main app in the bakstage repo.

Signed-off-by: Alex Crome <afscrome@users.noreply.github.com>

packages/create-app/templates/default-app/packages/backend/src/index.ts

@@ -104,6 +104,6 @@ async function main() {
 
 module.hot?.accept();
 main().catch(error => {
-  console.error(`Backend failed to start up, ${error}`);
+  console.error('Backend failed to start up', error);
   process.exit(1);
 });