maint: add repository archival notice

Signed-off-by: Yury V. Zaytsev <[email protected]>

Author: zyv

README

@@ -0,0 +1,9 @@
+# Midnight Commander's Legacy Repository
+
+⚠️ This repository has been archived! ⚠️
+
+It reflects the state just before we switched from Trac to GitHub for issue tracking on Feb 28, 2025.
+
+Please use the new repository at [MidnightCommander/mc](https://github.com/MidnightCommander/mc) instead!
+
+-- Maintainers