Add github pages deploy workflow

.github/workflows/docs.yml

@@ -0,0 +1,37 @@
+# Builds and publishes the documentation website to gh-pages branch
+name: Build docs
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup MSBuild
+        uses: microsoft/setup-msbuild@v1
+
+      - name: Restore NuGet Packages
+        run: msbuild -t:restore src\Bonsai.ZeroMQ.sln
+
+      - name: Setup DocFX
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install docfx
+
+      - name: Build Documentation
+        run: docfx docs/docfx.json
+
+      - name: Checkout gh-pages
+        uses: actions/checkout@v2
+        with:
+          ref: gh-pages
+          path: gh-pages
+      - name: Publish to github pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: docs/_site
+          force_orphan: true