Add composer.json to let PHP developers to keep track of annotator.js on packagist.org

[fabiomontefuscolo]

Hello!

I would like to propose the composer.json file and ask you to add you library on packagist.org. It will be easy to PHP developer keep track of your updates and refer your library as project dependency. I bet many CMS and blogs developers would take advantage of this facility.

Unfortunately, all I can do is propose this file. If you agree, you have more 3 steps:

i) create packagist.org account;
ii) submit your package and
iii) wire github webhooks in packagist

I would love to have your library on packagist.org