Update README.md with deprecation message

Author: tdelabro

README.md

@@ -1,3 +1,11 @@
+# DEPRECATED
+
+This repository is no longer supported, please consider using [madara](https://github.com/madara-alliance/madara) instead.
+
+This is due to our choice to shift to a non-substrate-based implementation.
+
+A huge thanks to everyone who contributed to this repository!
+
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