Examine source code of Nice Pull

{
  "manifest_version": 2,
  "name": "Nice Pull",
  "version": "1.4",
  "description": "Gives GitHub PR commits nice default names.",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://github.com/*/pull/*"
      ],
      "js": [
        "nicepull.js"
      ]
    }
  ]
}