Examine source code of Public GitHub header

{
  "manifest_version": 2,
  "name": "private-github-header",
  "version": "0.3.1",
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*"
      ],
      "js": [
        "private-github-header.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{588b842c-969a-450b-8c72-5073789b32d0}"
    }
  }
}