Update sponsors.md, link to the maintained list (#4251)

Author: devinivy

SPONSORS.md

@@ -1,10 +1,12 @@
-# Top Sponsors
-
-- Fabian Gündel / DataWrapper.de
-- Devin Stewart
+We'd like to thank our sponsors as well as the legacy sponsors who have supported hapi throughout the years. Thanks so much for your support!
 
-# Backers
+> Below are hapi's top recurring sponsors, but there are many more to thank.  For the complete list, see [hapi.dev/policies/sponsors](https://hapi.dev/policies/sponsors/) or [hapijs/.github/SPONSORS.md](https://github.com/hapijs/.github/blob/master/SPONSORS.md).
 
-- Aori Nevo
-- Zack McCartney
+# Staff Sponsors
+- [Big Room Studios](https://www.bigroomstudios.com/)
+- [Dixeed](https://dixeed.com/)
 
+# Top Sponsors
+- Fabian Gündel / [DataWrapper.de](https://www.datawrapper.de/)
+- Devin Stewart
+- [Raider.IO](https://raider.io/)