Add gitbook release documentation

RELEASE.md

@@ -141,15 +141,32 @@ unresolved issues still in the `X.Y.Z` milestone, then close the `X.Y.Z` milesto
 1. [Crates.io](https://crates.io/crates/solana) should have an updated Solana version.  This can take 2-3 hours
 
 ### Update documentation
-TODO: Documentation update procedure is WIP as we move to gitbook
 
-Document the new recommended version by updating `docs/src/running-archiver.md` and `docs/src/validator-testnet.md` on the release (beta) branch to point at the `solana-install` for the upcoming release version.
+After the release automation completes, to add the new release to the list of releases on docs.solana.com:
+1. Go to  https://www.gitbook.com/ and click on "Go To Dashboard"
+1. Find the "Solana Docs" project
+1. Under "Integrations" -> "Github", "Edit configuration". Add the new release to the "Select branches to sync" input box, tclick "Next ->" and then "Go live"
+1. Now find the new version in the drop down of imported releases and
+   toggle "Set as main variant" if `X.Y.Z` is now the latest release on the beta
+   channel.
+1. Consider deleting older `X.Y.Z-1` patch releases since they are no longer relevant
+1. "Save" the edits.
+2. "Merge" the edits
+
 
 ### Update software on devnet.solana.com/testnet.solama.com/mainnet-beta.solana.com
 
+#### devnet.solana.com
 ...
 
-### Alert the community
-
+##### Alert the community
 Notify Discord users on #validator-support that a new release for
 devnet.solana.com is available
+
+#### testnet.solana.com
+...
+
+
+#### mainnet-beta.solana.com
+...
+