Add a Dockerfile for buliding the docs

docs/Dockerfile

@@ -0,0 +1,13 @@
+FROM python:3-alpine
+
+RUN apk add --no-cache git
+
+COPY docs/requirements.txt requirements.txt
+RUN pip install -r /requirements.txt \
+ && mkdir /src
+
+WORKDIR /src
+COPY .git /src/.git
+
+RUN sphinx-versioning build -b -B 1.5 -r 1.5 -w '^[0-9.]*$' -w master -W '^$' /src /build
+

docs/requirements.txt

@@ -3,4 +3,3 @@ Sphinx
 sphinx-autobuild
 sphinx-rtd-theme
 sphinxcontrib-versioning
-paramiko