Update README.md

Signed-off-by: hericiumvevo <hericiumvevo@getcryst.al>

README.md

@@ -1,3 +1,9 @@
+# **THIS PROJECT HAS BEEN MIGRATED TO GITLAB**
+Please make any PRs here, rather than to the GitHub: https://git.getcryst.al/crystal
+
+# REPOSITORIES HERE ARE **OUTDATED**, GO TO THE LINK  BELOW
+# ---- > https://git.getcryst.al/crystal < ----
+
 <p align="center">
   <a href="https://github.com/crystal-linux/Malachite">
     <img src="https://getcryst.al/site/assets/other/logo.png" alt="Logo" width="150" height="150">