Improve documentation

[CWBudde]

While I'm aware of the fact, that the repository is not meant for end-users or users beyond your entity, but it would still be helpful to keep the documentation more up to date. As far as I can see, the existing beginner guide is written for the outdated v0.6.1
Given the fact that the compiler used for that version is hardly available on modern systems. It would make sense to point out that the latest version can be compiled with GCC 7 (correct me if I'm wrong).

In addition to that, several more packages are required in contrast to what is written in the tutorial. In particular when it comes to the python aspect (numpy and tensorflow). It might be trivial for those working with it every day, but not for beginners.

A lower entry level could help that science is not recognized as the ivory tower it looks like.