another attempt at preview builds

Author: nedbat

.github/workflows/preview.yml

@@ -0,0 +1,39 @@
+# pull_request and push event is supported.
+# This action also works for pull_request_target event, but should not be used in public repositories.
+# Please read https://securitylab.github.com/research/github-actions-preventing-pwn-requests/ before using this action with pull_request_target event.
+
+name: "Build PR preview"
+
+on:
+  workflow_dispatch:
+  #pull_request:
+  #push:
+  #  branches:
+  #    - master
+
+# contents: write is required for deploying the GitHub Pages if using the default GITHUB_TOKEN
+# pull-requests: write is required if you want to comment the preview page url to the pull request
+permissions:
+  pull-requests: write
+  contents: write
+
+# recommended to set a concurrency group
+concurrency:
+  group: preview-pages-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  run:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # run some build steps here and export the result to a directory
+
+      - name: Preview Pages
+        uses: rajyan/preview-pages@v1
+        with:
+          source-dir: .
+          target-branch: master
+          configured-domain: about.bostonpython.com