Added docker build environment

docker/Dockerfile

@@ -0,0 +1,83 @@
+## Build qmk-cli
+FROM python:3.8-slim-buster AS qmk_cli_builder
+WORKDIR /app
+COPY qmk_cli .
+RUN pip3 install build
+RUN python3 -m build
+
+
+## Base container
+FROM debian:11-slim
+
+# Install dependencies
+RUN apt-get update && \
+	apt-get install --no-install-recommends -y \
+	avrdude \
+	binutils-arm-none-eabi \
+	binutils-riscv64-unknown-elf \
+	build-essential \
+	ca-certificates \
+	clang-format-11 \
+	dfu-programmer \
+	dfu-util \
+	dos2unix \
+	ca-certificates \
+	gcc \
+	gcc-arm-none-eabi \
+	gcc-riscv64-unknown-elf \
+	git \
+	libfl2 \
+	libnewlib-arm-none-eabi \
+	picolibc-riscv64-unknown-elf \
+	python3 \
+	python3-pip \
+	software-properties-common \
+	tar \
+	teensy-loader-cli \
+	unzip \
+	tar \
+	wget \
+	zip \
+	&& rm -rf /var/lib/apt/lists/*
+
+# Install python packages
+RUN python3 -m pip install --upgrade \
+	pip \
+	setuptools \
+	wheel \
+	nose2 \
+	yapf
+
+# upgrade avr-gcc... for reasons?
+RUN /bin/bash -c "set -o pipefail && \
+	wget -q https://github.com/ZakKemble/avr-gcc-build/releases/download/v8.3.0-1/avr-gcc-8.3.0-x64-linux.tar.bz2 -O - | tee /tmp/asdf.tar.bz2 | md5sum -c <(echo '588D0BEA4C5D21A1A06AA17625684417  -') && \
+	tar xfj /tmp/asdf.tar.bz2 --strip-components=1 -C / && \
+	rm -rf /share/ /tmp/*"
+
+
+
+
+# Install qmk-cli
+COPY --from=qmk_cli_builder /app/dist /tmp/dist
+RUN python3 -m pip install /tmp/dist/qmk-*.whl && \
+	rm -rf /tmp/dist
+
+# Copy qmk repo.
+# Make sure you've pulled submodules first!
+COPY qmk_firmware /qmk_firmware
+RUN chmod -R 777 /qmk_firmware
+
+VOLUME /qmk_firmware/keyboards
+VOLUME /build_output
+WORKDIR /qmk_firmware
+
+ENV SKIP_GIT true
+
+COPY entrypoint.sh /entrypoint.sh
+CMD ["/bin/bash", "/entrypoint.sh"]
+
+# How to use:
+# docker run -it \
+#	--user 1000:1001 \
+#	-v "$(pwd)/kb:/qmk_firmware/keyboards" \
+#