Examine source code of Git.io

{
  "name": "Git.io",
  "version": "1.4",
  "description": "Shorten your GitHub urls to a git.io url.",
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "images/git_io_16.png",
      "32": "images/git_io_32.png",
      "48": "images/git_io_48.png",
      "128": "images/git_io_128.png"
    }
  },
  "commands": {
    "shorten-url-copy-to-clipboard": {
      "suggested_key": {
        "default": "Ctrl+Shift+L",
        "mac": "Command+Shift+L"
      },
      "description": "Shorten the url and copy it to the clipboard."
    }
  },
  "icons": {
    "16": "images/git_io_16.png",
    "32": "images/git_io_32.png",
    "48": "images/git_io_48.png",
    "128": "images/git_io_128.png"
  },
  "background": {
    "scripts": [
      "script/jquery.js",
      "script/functions.js",
      "script/background.js"
    ]
  },
  "permissions": [
    "tabs",
    "activeTab",
    "https://git.io/*"
  ],
  "manifest_version": 2
}