Examine source code of CodeCopy

{
  "manifest_version" : 2 ,
  "name" : "CodeCopy",
  "description" : "Because copy to clipboard buttons should exist on every code snippet",
  "homepage_url" : "https://github.com/zenorocha/codecopy",
  "version" : "0.4.1resigned1",
  "applications": {
    "gecko": {
      "id": "codecopy@clipboardjs.com",
      "strict_min_version": "45.0"
    }
  },
  "icons" : {
    "16" : "images/icon-16.png",
    "48" : "images/icon-48.png",
    "128" : "images/icon-128.png"
  },
  "content_scripts" : [
    {
      "css" : [
        "styles/main.css" 
      ],
      "js" : [
        "scripts/main.js" 
      ],
      "matches" : [
        "https://developer.mozilla.org/*" ,
        "https://medium.com/*" ,
        "https://www.npmjs.com/*" ,
        "https://github.com/*" ,
        "https://gist.github.com/*" ,
        "http://stackexchange.com/*" ,
        "https://stackexchange.com/*" ,
        "http://*.stackexchange.com/*" ,
        "https://*.stackexchange.com/*" ,
        "https://serverfault.com/*" ,
        "https://superuser.com/*" ,
        "https://askubuntu.com/*" ,
        "http://stackoverflow.com/*" ,
        "https://stackoverflow.com/*" 
      ]
    }
  ]
}