Examine source code of Git-PP

{
  "manifest_version": 2,
  "name": "Git-PP",
  "version": "1.0",
  "description": "Adds a button to GitHub homepage that takes you to your profile",
  "content_scripts": [
    {
      "matches": [
        "*://github.com/"
      ],
      "js": [
        "git-pp.js"
      ]
    }
  ]
}