Apply suggestions to README from code review

Co-authored-by: Mehdi Bendriss <bendrissmehdi@gmail.com>

README.md

@@ -1,7 +1,7 @@
-Charmed Valkey rock
+# Charmed Valkey rock
 This repository will contain the packaging metadata for creating a rock of Charmed Valkey built from Charmed Valkey 
 Snap.
 
-License
+## License:
 The Charmed Valkey rock is free software, distributed under the Apache Software License, version 2.0. See licenses for 
 more information.