add graalvm native image configures

src/main/kotlin/space/mori/chzzk_bot/services/UserService.kt

@@ -0,0 +1,21 @@
+package space.mori.chzzk_bot.services
+
+import space.mori.chzzk_bot.Database
+import space.mori.chzzk_bot.discord.User
+
+class UserService {
+    fun saveUser(user: User) {
+        val session = Database.sessionFactory.openSession()
+        session.beginTransaction()
+        session.persist(user)
+        session.transaction.commit()
+        session.close()
+    }
+
+    fun getUser(id: Long): User? {
+        val session = Database.sessionFactory.openSession()
+        val user = session.get(User::class.java, id)
+        session.close()
+        return user
+    }
+}