Move XRootD Evolution link to point to GitHub projects

Author: amadio

evolution.md

@@ -1 +1,7 @@
-[See our current direction](https://docs.google.com/spreadsheets/d/1wSxPNiPJr4mLjUUhwWsx_fHIGeEUm5buJ6lMRQUGD8o/view?gid=0#gid=0).
+---
+layout: default
+title:  XRootD Evolution
+tab:    evolution
+---
+
+The future of XRootD is managed directly in GitHub projects. [See our current direction](https://github.com/orgs/xrootd/projects).