Added docs into services

buisnesslogic/src/main/java/com/plannaplan/services/UserService.java

@@ -12,6 +12,9 @@ import com.plannaplan.types.UserRoles;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+/**
+ *  Service of UserService which can get(By Email), login, save user.
+ */
 @Service
 public class UserService {
     @Autowired