add release instructions in CONTRIBUTING.md (#54)

CONTRIBUTING.md

@@ -7,6 +7,7 @@
 - [Run tests](#run-tests)
 - [Setup examples](#setup-examples)
 - [Build](#build)
+- [Release](#release)
 
 ## Prerequisites
 
@@ -45,3 +46,21 @@ If you need to regenerate the OpenAPI-generated, use the script:
 npm run clean
 npm run build
 ```
+
+## Release
+
+When you are ready to release, make sure the version in package.json has been bumped. Then create a [GitHub Release](https://github.com/sajari/sdk-node/releases).
+
+You can use the `gh` CLI tool to create a release or you can use [GitHub.com](https://github.com/sajari/sdk-node/releases/new).
+
+An example `gh` looks something like this:
+
+```
+gh release create v4.5.1 --generate-notes --draft
+```
+
+Note: The draft needs to be published, which can be done at the printed URL.
+
+Note: The format of the release tag should be `vx.x.x` e.g. `v4.5.1`.
+
+Creating a release triggers a [GitHub Action](.github/workflows/npm-publish.yml) that publishes the package to NPM.