create feed specific scripts which can check for new GTFS data and can download those

[osm-ToniE]

options?

• -c check only and create an empty *.db file (touch) if that file does not already exist
  this is an indicator that a new version is available but has not yet been downloaded and prepared

• d download and store in a directory with the date of the release (i.e. 2020-09-01/*zip)

Each provider of GTFS data has his own method of providing links, so this must be handled individually

Provide also a gtfs-all-feeds script which calls all individtal scripts (with -c in a cron-job?)

[osm-ToniE]

duplicate to issue #3 which has been create before under ptna-www and transferred here afterwards