(docs): use gh actions to deploy documentation (#616)

.github/workflows/docs.yml

@@ -0,0 +1,30 @@
+# * docs.yml --- Build the documentation and publish to Github Pages
+
+name: "Docs"
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: true
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install deps
+      run: |
+        sudo apt-get install makeinfo
+
+    - name: Build docs
+      continue-on-error: false
+      run: make html
+
+    - name: Deploy 🚀
+      uses: JamesIves/github-pages-deploy-action@releases/v3
+      with:
+        ACCESS_TOKEN: ${{ secrets.ACCESS_TOKEN }}
+        BRANCH: gh-pages # The branch the action should deploy to.
+        FOLDER: doc # The folder the action should deploy.

.github/workflows/test.yml

@@ -29,7 +29,6 @@ on:
   push:
     branches:
       - master
-      - develop
 
 jobs:
   build: