Replace esp-web-tools with esptool-js and fix local webserver

.github/workflows/deploy.yml

@@ -0,0 +1,43 @@
+name: Deploy
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: pages-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      # package-lock.json is not committed, so "npm ci" is not an option
+      - run: npm install
+      - run: npm run build
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist
+
+  deploy:
+    if: github.event_name != 'pull_request'
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4

README.md

@@ -20,7 +20,10 @@ Building static files into `dist/`:
 npm run build
 ```
 
-Copy manually to `docs/` and perform git push to deploy,
+# Deployment
+
+Pushing to `main` builds the site and deploys it to GitHub Pages with the
+[Deploy workflow](.github/workflows/deploy.yml).
 
 # License