First draft release workflow

I haven’t done this before… let’s see how I get on.

Author: csswizardry

.github/workflows/release.yml

@@ -0,0 +1,44 @@
+name: release
+
+on:
+  push:
+    tags:
+      - '*.*.*'
+      - '*.*.*-*'
+
+permissions:
+  contents: write
+
+jobs:
+  build-and-release:
+    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 deps
+        run: npm ci
+
+      - name: Build obs.min.js
+        run: npm run build
+
+      - name: SHA256 checksum
+        run: shasum -a 256 obs.min.js > SHA256SUMS.txt
+
+      - name: Create GitHub Release and upload assets
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ github.ref_name }}
+          name: 'Obs.js ${{ github.ref_name }}'
+          generate_release_notes: true
+          files: |
+            obs.min.js
+            SHA256SUMS.txt
+