Add docker file

ci/mkdocs/Dockerfile

@@ -0,0 +1,7 @@
+FROM python:3.13-slim
+
+WORKDIR /work
+
+COPY requirements.txt /tmp/requirements.txt
+
+RUN pip install --no-cache-dir -r /tmp/requirements.txt

ci/mkdocs/requirements.txt

@@ -0,0 +1,3 @@
+mkdocs==1.6.1
+mkdocs-material==9.7.3
+pymdown-extensions==10.21