Update testnet link and add Open Boards link

Removed test7 and added test9 and added Open Boards forum link.

Author: michelleellen

examples/gno.land/r/gnoland/home/home.gno

@@ -82,8 +82,9 @@ the foundations of a fairer and freer world, join us today.
 - [Discover demo packages](https://github.com/gnolang/gno/tree/master/examples)
 - [Gnoscan](https://gnoscan.io)
 - [Staging chain](https://docs.gno.land/resources/gnoland-networks/#staging-environments-portal-loops)
-- [Testnet 7](https://test7.testnets.gno.land/)
+- [Testnet 9](https://test9.testnets.gno.land/)
 - [Faucet Hub](https://faucet.gno.land)
+- [Open Boards, a social discussion forum](https://gno.land/r/boards000/v1rc1:General
 
 </gno-columns>