AR.js maintainers needed

[nickw1]

There are a number of outstanding issues with AR.js. I, along with others, am one of the more recent maintainers but unfortunately have little or no available time for AR.js at the moment. I may be able to check and merge small PRs but I'm unlikely to have the time to do major bug fixes. Apologies for this but life, and other projects, have got in the way.

It would be great to see the project move forwards so would be good to get some volunteers to help out maintaining the project. Contributors with iOS devices would be particularly welcome.

@kalwalt @nicolocarpignoli Please note the above.