Add workflow

.github/workflows/sphinx.yml

@@ -0,0 +1,31 @@
+name: "Sphinx: Build Fortran90.org"
+
+on:
+  push:
+    branches: ["master"]
+
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build HTML
+      uses: ammaraskar/sphinx-action@master
+      with:
+        docs-folder: "./"
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: html-docs
+        path: _build/html/
+    - name: Deploy
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: _build/html