Add check for building docsite

.github/workflows/ci.yml

@@ -7,6 +7,9 @@ env:
   COMPOSE_TAG: ${{ github.base_ref || 'devel' }}
 on:
   pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - '.github/workflows/docs.yml'
 jobs:
   common-tests:
     name: ${{ matrix.tests.name }}

.github/workflows/docs.yml

@@ -0,0 +1,19 @@
+---
+name: Docsite CI
+on:
+  pull_request:
+    paths:
+      - 'docs/**'
+      - '.github/workflows/docs.yml'
+jobs:
+  docsite-build:
+    name: docsite test build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: install tox
+        run: pip install tox
+
+      - name: Assure docs can be built
+        run: tox -e docs