Remove AUTHORS

[Tyriar]

I think https://github.com/xtermjs/xterm.js/graphs/contributors is better than keeping everyone in the AUTHORS file. GitHub's UI intentionally makes it tricky to pull people's emails.

[Tyriar]

Problem with the generate-authors script on macOS:

tail: illegal option -- -
usage: tail [-F | -f | -r] [-q] [-b # | -c # | -n #] [file ...]

[Tyriar]

The only place that the AUTHORS file is referenced is on the website, we should replace those references if we want to do this. https://github.com/xtermjs/xtermjs.org