ci(documentation): add the dockerfile

tools/ci/documentation.dockerfile

@@ -0,0 +1,27 @@
+FROM alpine:latest
+
+RUN apk add --no-cache \
+    bash \
+    clang \
+    llvm \
+    cmake \
+    git \
+    make \
+    g++ \
+    python3 \
+    py3-pip \
+    mesa-dev \
+    mesa-gl \
+    pkgconf \
+    clang-extra-tools \
+    mold \
+    ninja \
+    doxygen \
+    openssh
+
+RUN pip install --no-cache-dir --break-system-packages \
+    conan \
+    gitpython \
+    Sphinx \
+    sphinx_rtd_theme \
+    && conan profile detect