Examine source code of Goodratings

{
  "manifest_version": 2,
  "name": "Goodratings",
  "version": "2.1.0",
  "description": "Changes the way ratings on Goodreads are displayed.",
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.goodreads.com/*"
      ],
      "js": [
        "gr.js"
      ]
    }
  ]
}