feat: added UserDetailsServiceImpl

src/main/java/com/example/nto/service/impl/UserDetailsServiceImpl.java

@@ -0,0 +1,14 @@
+package com.example.nto.service.impl;
+
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.stereotype.Service;
+
+@Service
+public class UserDetailsServiceImpl implements UserDetailsService {
+    @Override
+    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
+        return null;
+    }
+}