Examine source code of Raw Githack

{
  "name": "Raw Githack",
  "version": "0.1",
  "description": "Viewing html files with raw.githack.com made easier.",
  "permissions": [
    "tabs"
  ],
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon/16.png",
      "32": "icon/32.png",
      "48": "icon/48.png",
      "128": "icon/128.png"
    }
  },
  "manifest_version": 2
}