Update release instructions

Author: cknitt

CONTRIBUTING.md

@@ -389,6 +389,8 @@ To build a new version and release it on NPM, follow these steps:
    npm publish rescript-std-<version>.tgz [--tag next]
    ```
 1. Tag the commit with the version number (e.g., "10.0.0", or "10.0.0-beta.1") and push the tag.
+1. Create a release entry for that tag on the [Github Releases page](https://github.com/rescript-lang/rescript-compiler/releases), copying the changes from `Changes.md`.
+1. Coordinate any forum/blog posts with [@ryyppy](https://github.com/ryyppy).
 
 ## Contribution Licensing