Add attempt at a docker image for the toolchain

contrib/Dockerfile

@@ -0,0 +1,71 @@
+FROM ubuntu:22.04
+
+RUN apt-get -qq update -y \
+    && DEBIAN_FRONTEND=noninteractive \
+       apt-get install -y --no-install-recommends \
+               bison \
+               build-essential \
+               ca-certificates \
+               clang \
+               cmake \
+               flex \
+               gawk \
+               git \
+               golang \
+               graphviz \
+               less \
+               libboost-dev \
+               libboost-filesystem-dev \
+               libboost-iostreams-dev \
+               libboost-program-options-dev \
+               libboost-thread-dev \
+               libeigen3-dev \
+               libffi-dev \
+               libftdi-dev \
+               libreadline-dev \
+               lld \
+               llvm \
+               mercurial \
+               nano \
+               pkg-config \
+               python3 \
+               python3-dev \
+               tcl-dev \
+               verilator \
+               vim \
+               xdot \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN git clone --depth=1 https://github.com/YosysHQ/icestorm /src
+WORKDIR /src
+RUN make -j$(nproc --ignore=2) \
+    && make install
+RUN git show -s >/repo-commit-icestorm
+WORKDIR /
+RUN rm -rf /src
+
+RUN git clone --depth=1 https://github.com/tillitis/icestorm /src
+WORKDIR /src/iceprog
+RUN make -j$(nproc --ignore=2) \
+    && make PROGRAM_PREFIX=tillitis- install
+RUN git show -s >/repo-commit-tillitis--icestorm
+WORKDIR /
+RUN rm -rf /src
+
+RUN git clone https://github.com/YosysHQ/yosys /src
+WORKDIR /src
+RUN git checkout 06ef3f264afaa3eaeab45cc0404d8006c15f02b1 \
+    && make -j$(nproc --ignore=2) \
+    && make install
+RUN git show -s >/repo-commit-yosys
+WORKDIR /
+RUN rm -rf /src
+
+RUN git clone --depth=1 https://github.com/YosysHQ/nextpnr /src
+WORKDIR /src
+RUN cmake -DARCH=ice40 -DCMAKE_INSTALL_PREFIX=/usr/local . \
+    && make -j$(nproc --ignore=2) \
+    && make install
+RUN git show -s >/repo-commit-nextpnr
+WORKDIR /
+RUN rm -rf /src