Assets/Create下にエディタ拡張を追加する

NewScriptSettingCreator.cs

namespace ScriptNamespace
{
	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;
    using UnityEditor;
    public class NewScriptSettingCreator : Editor {
        [MenuItem ("Assets/Create/ScriptNamespace/NewScriptSetting")]
        static void Create(){
            var instance = CreateInstance<NewScriptSetting>();
            AssetDatabase.CreateAsset(instance, "Assets/Resources/NewScriptSetting.asset");
            AssetDatabase.Refresh();
        }
	}
}