text: const mongoose = require('mongoose');
  const Schema = mongoose.Schema;
  
  const UserSchema = new Schema({
      username: {
          type: String,
          required: true, // zorunlu
          unique: true // benzersiz
      },
      password: {
          type: String,
          minlength: 5
      }
  });
  
  module.exports = mongoose.model('user', UserSchema);
  