docker/tools: build script and Dockerfile work now

tools/Dockerfile

@@ -0,0 +1,10 @@
+# Set up a packer image in Docker.
+FROM ubuntu:22.04
+LABEL org.opencontainers.image.authors=kyle@imap.cc
+
+RUN apt-get update && apt-get -y install git bash curl sudo
+
+ADD . tools
+RUN tools/install-go.sh
+
+ENTRYPOINT ["/usr/bin/env", "bash"]