Document and track container configuration

[j-i-l]

We should also explicitly declare what packages and versions thereof a container installs.

This is especially important since our configuration creates new containers each month and we do, a priori, not know if, and if yes what kind of changes, there are in the new container.

We could track the configuration in a separate file and the changes can be explored when clicking on the newly created tag in the CHANGELOG.md file.

[j-i-l]

Wirte out the container config by means of a .Rmd file into a well formatted .md file