Run documentation

[dmcgowan]

Currently the readme contains an example for setting up a golem test, but nothing for how to run golem. Documentation is needed to specify how to build/install golem as well as use its various options. The differences between running for dev-build-test flow and ci flow should also be highlighted.

[pouyanh]

+1

[atodorov]

As far as I understand golem is able to run tests which are outside of the docker image, for example run a selenium test against a web instance. I also want to run some test scripts inside of the docker image, once it is running. This should also be documented.