Update contributing.md

Author: jdalton

CONTRIBUTING.md

@@ -1,3 +1,7 @@
 # Publishing a new version
 
-This repository uses `npm` provided provenance using GitHub Actions, please update the version in `package.json` using an appropriate tag and create a release using GitHub, the `.github/workflows/provenance.yml` action should publish it to `npm` from there.
+This repository uses `pnpm` and npm provenance through GitHub Actions. To publish a new version:
+
+1. Update the version in `package.json`
+2. Create a release using GitHub with an appropriate tag
+3. The `.github/workflows/provenance.yml` action will automatically publish it to npm