ci: add workflow for automatic npm publishing on release (#98)

## Summary
- Add GitHub Actions workflow that automatically publishes to npm when a
GitHub release is created
- Workflow runs tests and linting before publishing to catch issues
- Uses the existing `prepublishOnly` hook to run minification

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Author: robertodauria

.github/workflows/publish.yml

@@ -0,0 +1,34 @@
+name: Publish to npm
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v6
+
+    - name: Setup Node.js
+      uses: actions/setup-node@v6
+      with:
+        node-version: 20
+        cache: 'npm'
+        registry-url: 'https://registry.npmjs.org'
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Run tests
+      run: npm test
+
+    - name: Run linter
+      run: npm run lint
+
+    - name: Publish to npm
+      run: npm publish --access public
+      env:
+        NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}