Add documentation github workflow

Author: stijnh

.github/workflows/documentation.yml

@@ -0,0 +1,38 @@
+name: Build documentation
+
+on:
+  push:
+    branches: [ main ]
+  workflow_dispatch:
+
+jobs:
+  build:
+    permissions:
+      id-token: write
+      pages: write
+      contents: write
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: 'recursive'
+          fetch-depth: 0 # otherwise, you will failed to push refs to dest repo
+      - name: Setup Julia
+        uses: julia-actions/setup-julia@v1
+        with:
+          version: "1.11"
+      - name: Build Julia documentation and deploy
+        run: |
+          touch src/Constants.jl
+          julia --project=docs -e '
+            using Pkg
+            Pkg.develop(PackageSpec(path=pwd()))
+            Pkg.instantiate()
+          '
+          julia --project=docs docs/make.jl
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # If authenticating with GitHub Actions token
+          DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }} # If authenticating with SSH deploy key