add firefox extension template

externs/webextension_polyfill/notifications/CreateNotificationOptions.hx

@@ -0,0 +1,70 @@
+package webextension_polyfill.notifications;
+
+typedef CreateNotificationOptions = {
+	/**
+		Which type of notification to display.
+	**/
+	var type : TemplateType;
+	/**
+		A URL to the sender's avatar, app icon, or a thumbnail for image notifications.
+		Optional.
+	**/
+	@:optional
+	var iconUrl : String;
+	/**
+		A URL to the app icon mask.
+		Optional.
+	**/
+	@:optional
+	var appIconMaskUrl : String;
+	/**
+		Title of the notification (e.g. sender name for email).
+	**/
+	var title : String;
+	/**
+		Main notification content.
+	**/
+	var message : String;
+	/**
+		Alternate notification content with a lower-weight font.
+		Optional.
+	**/
+	@:optional
+	var contextMessage : String;
+	/**
+		Priority ranges from -2 to 2. -2 is lowest priority. 2 is highest. Zero is default.
+		Optional.
+	**/
+	@:optional
+	var priority : Float;
+	/**
+		A timestamp associated with the notification, in milliseconds past the epoch.
+		Optional.
+	**/
+	@:optional
+	var eventTime : Float;
+	/**
+		A URL to the image thumbnail for image-type notifications.
+		Optional.
+	**/
+	@:optional
+	var imageUrl : String;
+	/**
+		Items for multi-item notifications.
+		Optional.
+	**/
+	@:optional
+	var items : Array<NotificationItem>;
+	/**
+		Current progress ranges from 0 to 100.
+		Optional.
+	**/
+	@:optional
+	var progress : Float;
+	/**
+		Whether to show UI indicating that the app will visibly respond to clicks on the body of a notification.
+		Optional.
+	**/
+	@:optional
+	var isClickable : Bool;
+};