Create an help to use predefined labels/issues boards/milestones

Create a document to explain the predefined labels/issues boards/milestones and how they should be used to enable an efficient management of issues tracking.

changed milestone to %ThermoSysPro v4.1

added infrastructure label

Maybe it should be added to the ContributionsWorkflow.md? Do you think it is the right place @giorgio.simonini ? Or README ?

It is not clear in my mind what's the best place for that. Do not you think that the issue template (see #58 (closed)) could be enough for that ?

For sure a section with an explaination of the milstone (roadmap) sould be added to the README (see #54 (closed)).

Otherwise, we can start writing something and then see what's the best place to put it. ;)

From what I've seen elsewhere, it is mainly developers who put labels on issues (after it has been written) and not the reporters (in the case where issues can be created from people outside of TSP team). That's why I am not sure that issue template is the right place but indeed we can start by writing a few lines on the subject!

changed milestone to %ThermoSysPro v4.2