Move website builds to GitLab CI

Repo cloning will go by next week.

Signed-off-by: Andrei Jiroh Halili <ajhalili2006@gmail.com>

docker/build.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -xe
+
+ROOTDIR=$(git rev-parse --show-toplevel)
+CONTEXT=$ROOTDIR/docker
+DOCKERFILE=$CONTEXT/Dockerfile
+TAG=${IMAGE_TAG:-"quay.io/ajhalili2006/mkdocs-material-build-ci:localdev"}
+
+DOCKER_BUILDKIT=${DOCKER_BUILDKIT:-"0"} \
+  docker build \
+  -t $TAG \
+  -f "$DOCKERFILE" \
+  "$CONTEXT"