Hosting the catalog on GitHub

[opk12]

1. Could you change the "browse catalog" URL from Google Drive to GitHub?

2. If you do 1, please also upload one zip file for each language, otherwise one must download a lot of files manually. Related issue is [Feature request] Mass import #81.

Additional context

This future-proofs the app, if the maintainer becomes inactive; and helps third-party forks.

• The catalog can be in the source tree or its own repo.
• If the catalog is very big, the build process can ignore it.

The cons of using Google Drive are

• Google can delete the Drive, if the account owner is inactive for a long time.
  • In fact, the owner is appearing now as boy's photo + undefined / "User could not be loaded"
• Cannot download a language's folder on mobile. The download button does not exist in the Google Drive mobile version.
  • I can either download the folder from the PC, or download a single card on mobile.
  • The URL is very long and hard to type by hand on a PC: https://drive.google.com/folderview?id=1sjHdkcChH2CvUi3jmhf--PNeVmA_716W
• The cards don't have a license.

The pros of using GitHub are

• GitHub does not delete repos of inactive maintainers.
• Via pull requests, the community can easily contribute cards.
• If the cards are in the source tree repo, they inherit the license, so they can be reused in third-party forks.