JSON format for tool integration on HEPData

As discussed in Grenoble, it would be a step forward if the different interpretation tools linked their analysis implementations to the corresponding entries on HEPData, making them findable. Rivet and MadAnalysis have already provided these JSON files. SModelS, CheckMATE, HackAnalysis, ADL (and maybe Contur/Gambit?) will hopefully follow soon.

As a start, it would be good to agree on a format for the JSON that makes it useable for the different needs of the various tools. Maybe we can discuss here what that format should look like. (We can also move the discussion elsewhere, e.g. the OpenMAPP wiki or a separate OpenMAPP project, if preferred.) As soon as we settled on something, I'm happy to help with implementing changes in HEPData if necessary.