Add GitHub publish workflow

Change-Id: Id3810d227e13c567f5f000eb5c43774fc739675a

Author: TristanCacqueray

.github/workflows/pelican.yml

@@ -0,0 +1,15 @@
+name: Deploy to GitHub Pages
+on:
+  push:
+    branches: ["master"]
+  workflow_dispatch:
+jobs:
+  deploy:
+    uses: "getpelican/pelican/.github/workflows/github_pages.yml@main"
+    working-directory: "website"
+    permissions:
+      contents: "read"
+      pages: "write"
+      id-token: "write"
+    with:
+      settings: "publishconf.py"