[NTG-context] new module installer and .tar.gz compression

Hans, many thanks for the new script to install modules in LMTX. I forced a new release of handlecsv (https://modules.contextgarden.net/cgi-bin/module.cgi/action=view/id=86). I provide the contents with a git address, so I cannot choose which kind of compression the code will have. Since imports from git use .tar.gz, these modules cannot be installed with the script (which seems to expect .zip compression exclusively). Sorry, but I don’t know how to force git urls to be added as zip packages in https://modules.contextgarden.net. Many thanks for your help, Pablo