Examine source code of Shut Up, Github!

{
  "manifest_version": 2,
  "name": "Shut Up, Github!",
  "version": "0.3",
  "description": "Removes the notification icon from the GitHub topbar.",
  "content_scripts": [
    {
      "matches": [
        "*://*.github.com/*"
      ],
      "js": [
        "index.js"
      ]
    }
  ]
}