Improve debugging documentation

[BjoernLudwigPTB]

@gertjan123 asked a while ago:

The Dashboard is causing some trouble, and possibly the agent network as well. They load quite slowly. It would be very nice if one can launch and debug an application in three steps:

1. Only algorithms
2. Agents without dashboard.
3. Full application with agents and dashboard.

Is there an elegant way to do this, or does this depend on the modularity of my own files and additional test scripts?

Maybe we could extend the docs with a section covering debugging and this specific requirement. As far as I can see, this is possible as of now if, as suggested, the code is structured accordingly.