Update README to reflect legacy status of website

Clarified the status of the website and provided links to the current version and repository.

Author: alexsb

README.md

@@ -1,4 +1,9 @@
-# Vis Design Lab Website
+# Legacy Vis Design Lab Website
+
+This is the pre-2025 version of the VDL website. It is no longer maintained but available for archival purposes. 
+For the current website, visit https://visdesignlab.net and the repository at https://github.com/vdl-website/vdl-website.github.io
+
+# Old Content
 
 The Vis Design Lab website is based on the Caleydo website and built with
 [Jekyll](http://jekyllrb.com).
@@ -116,4 +121,4 @@ This page uses the following modules:
     * `gem 'jekyll-redirect-from'`
     * https://github.com/jekyll/jekyll-redirect-from
   * addressable
-  * public_suffix
+  * public_suffix