update releasing

Author: cijothomas

RELEASING.md

@@ -42,6 +42,8 @@ A draft PR can be created, but before releasing consider the following:
 5. [Publish](#publishing-crates) to crates.io using the version as of the release commit
 6. Post to [#otel-rust](https://cloud-native.slack.com/archives/C03GDP0H023) on CNCF Slack.
 
+[Publish.sh](./scripts/publish.sh) may be used to automate steps 3 and 5.
+
 ## Tagging Convention
 
 For each crate: it should be `<crate-name>-<version>` `<version>` being the simple `X.Y.Z`.