explain official end of development for this code

README.markdown

@@ -1,3 +1,15 @@
+# This Version of Timeline is no longer under development
+
+Knight Lab has created a new version at https://github.com/NUKnightLab/TimelineJS3 . The new library should work with existing Google Spreadsheets, but not existing TimelineJS JSON files. Knight Lab will continue to serve this version of Timeline from
+
+* https://cdn.knightlab.com/libs/timeline/latest/js/timeline-min.js
+* https://cdn.knightlab.com/libs/timeline/latest/js/timeline.js
+* https://cdn.knightlab.com/libs/timeline/latest/css/timeline.css
+
+However, no future development on this line of code is planned.
+
+----
+
 **Table of Contents**
 
 - [TimelineJS](#timelinejs)
@@ -453,5 +465,3 @@ Tips and tricks to best utilize TimelineJS
 This Source Code Form is subject to the terms of the Mozilla Public
 License, v. 2.0. If a copy of the MPL was not distributed with this
 file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-