using a pseudo-syntax here
please note: this are all ideas from the top of my head, I don't know the new generator at all, so please correct me where these ideas are redundant, unwise or infeasable
qx contrib listlists all available contributions on github with the topic 'qx-contrib' that are compatible with the current library,--allfor allqx contrib install <contrib name>: downloads the given contrib and adds its manifest to config.json. If is omitted, all contribs inconfig.json/jobs/librariesthat have a github URL are downloaded.qx contrib remove <contrib name>: removes the given contrib from the filesystem and from config.jsonqx contrib update: updates the given contrib,--allto update all contribs to the latest compatible version