Update site URLs in README.md
The Dagger (XDAG) cryptocurrency
================================
-- Official site: http://xdag.me
+- Community site: https://xdag.io - Developer's site: http://xdag.me
- Main net is launched January 5, 2018 at 22:45 GMT.
@@ -10,7 +10,7 @@ Principles:
- Directed acyclic graph (DAG), not blockchain
- Block = transaction = address
-- Original main chain idea
+- Original idea and implementation
- Mineable, no premine, no ICO
- Mining new money every 64 seconds
