fix: update import path for db in drizzle.tsx (#277)

Update import path for db in drizzle.tsx

Caused an error when I tried the drizzle option

Author: vkalahas

frameworks/react-cra/add-ons/drizzle/assets/src/routes/demo/drizzle.tsx

@@ -1,6 +1,6 @@
 import { createFileRoute, useRouter } from '@tanstack/react-router'
 import { createServerFn } from '@tanstack/react-start'
-import { db } from '@/db'
+import { db } from '@/db/index'
 import { desc } from 'drizzle-orm'
 import { todos } from '@/db/schema'