Use material theme

Dockerfile

@@ -1,6 +1,9 @@
 FROM python:3.12-slim AS builder
 
 WORKDIR /docs
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    libcairo2 \
+    && rm -rf /var/lib/apt/lists/*
 COPY pyproject.toml ./
 RUN pip install .
 COPY mkdocs.yml .