Not able to run a demo - is README.md updated ?

[Bhogayata-Keval]

I wanted to explore what kind of data is collected by the collectors built here.
I built the flowmill-collector project, which gave me a set of docker images. But, I was expecting a docker image with name "build-env", which is needed to build the kernel-collector.

So can anyone help me out here.
Step 1 : Running ./build.sh on https://github.com/Flowmill/flowmill-build-env
..... I guess I am missing something here .................
Last steps : As explained in the README.md