Tracker: User Friendly Docker-based MathHub Worker

[kohlhase]

We want to realize the concept of MathHub workers as private docker containers that users can download and directly get started. There are a couple of interactions the user needs for initialization and getting started

• key configuration, see key configuration #3
• libraries/repos config (the set of libraries in this docker) (see library/repos configuration #6)
• managing and updating software dependencies (see managing and updating software dependencies #5)
• Hello World Libraries to have examples (see Hello World libraries as examples #2)
• Getting started help pages (getting started/help pages #7)
• worker update guide and interactions (docker worker update process #8).