Add some more docs and streamline entrypoint

examples/fullstack/backend/database/seeders/user_seeder.ts

@@ -4,6 +4,11 @@ import { faker } from '@faker-js/faker'
 
 export default class extends BaseSeeder {
   public async run () {
+    const usersExist = await User.query().first()
+    if (usersExist) {
+      console.log('Database already seeded, skipping...')
+      return 
+    }
     const users = Array.from({ length: 1000 }).map(() => ({
       fullName: faker.person.fullName(),
       email: faker.internet.email(),