Test if docs can build in CI

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-name: linkcheck
+name: CI
 
 on:
   push:
@@ -8,8 +8,19 @@ on:
   workflow_dispatch:
 
 jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Build docs
+        run: bash ci/docker-build.sh
+
+
   linkcheck:
      runs-on: ubuntu-latest
+
      steps:
       - uses: actions/checkout@v2
 

ci/build-requirements.txt

@@ -0,0 +1 @@
+mkdocs

ci/docker-build.sh

@@ -0,0 +1,16 @@
+#! /bin/bash
+
+set -e
+set -o pipefail
+set -x
+
+this_dir="$(readlink -f -- "$(dirname -- "${BASH_SOURCE[0]}")")"
+image="python:3-alpine"
+
+# as we use a pipe to stdin and thus cannot use -it, Ctrl-C does not work by default
+# turns out that combining -i with --init solves that problem
+# see https://stackoverflow.com/a/60812082
+docker run --rm -i -v "$this_dir"/..:/ws -w /ws --init "$image" sh <<\EOF
+    pip install -r ci/build-requirements.txt
+    mkdocs build
+EOF