Add requirements.txt to manage dependencies and update readme

When creating a configuration file, users need to know what categories and languages are available. That information can be found here

added support for tags, YT channel language fetching and peertube categories

Added ability to use PeerTube HTTP import, readme updated with information on this feature.

Added ability to use PeerTube HTTP import, issue #8, updated the readme to explain this option.

Depending on the config, the tool no longer needs to download and upload videos if the user does not want to.

Added config parameter to use Peertube HTTP import rather than downloading and uploading videos. Default false.