github workflow for publishing an observable framework

To publish an observable framework website on github pages is a 2-step procedure:

1. Go to settings -> pages (The URL will be https://github.com/<user>/<repo>/settings/pages) and change the "source" dropdown from "deploy from a branch" to "Github Actions"
2. Add the file below to the repository as .github/workflows/publish.yml
3. That's it! Every time you push a change to the main branch you'll get an updated website.

name: Publish
on:
  workflow_dispatch:
  push:
    branches: ["main"]
permissions:
  contents: write
jobs:
  build:
    concurrency: ci-${{ github.ref }} # Recommended if you intend to make multiple deployments in quick succession.
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup node
        uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: "npm"

      - name: Install dependencies
        run: npm ci

      - name: Build
        run: npm run build

      - name: Upload artifact
        uses: actions/upload-pages-artifact@v3
        with:
          path: ./dist

  deploy:
    needs: build
    permissions:
      pages: write
      id-token: write
    environment:
      name: github-pages
      url: ${{ steps.deployment.outputs.page_url }}
    runs-on: ubuntu-latest
    steps:
      - name: Deploy to GitHub Pages
        id: deployment
        uses: actions/deploy-pages@v4