Added Post system. Notification system

src/main/java/site/easystartup/web/notification/event/NotificationEvent.java

@@ -0,0 +1,9 @@
+package site.easystartup.web.notification.event;
+
+public interface NotificationEvent {
+    void invoke();
+
+    String getRecipient();
+
+    String getMessage();
+}