Update RELEASING.md

Author: jonrohan

RELEASING.md

@@ -31,7 +31,7 @@ The release process is automated by [changesets]. After you familiarize yourself
 
     After tests run, the docs site will be deployed and `@primer/css` will be published with your changes to the `latest` dist-tag. You can check [npm](https://www.npmjs.com/package/@primer/css?activeTab=versions) to see if actions has finished.
 
-2. done 🎉
+2. Done! 🎉
 
 
 ## Update github.com (in `github/github`):