Examine source code of GitHub Static Branch

{
  "manifest_version": 2,
  "name": "GitHub Static Branch",
  "short_name": "GH Static Branch",
  "version": "0.1",
  "developer": {
    "name": "Fionn",
    "url": "https://github.com/fionn/github-static-branch"
  },
  "description": "Remove GitHub instructions that move your branches",
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*/*"
      ],
      "exclude_matches": [
        "https://github.com/settings/*",
        "https://github.com/organizations/*",
        "https://github.com/notifications/*",
        "https://github.com/explore/*",
        "https://github.com/marketplace/*",
        "https://github.com/pulls/*",
        "https://github.com/issues/*",
        "https://github.com/*/settings",
        "https://github.com/*/settings/*",
        "https://github.com/*/*/*",
        "https://github.com/new/*"
      ],
      "js": [
        "content/main.js"
      ],
      "run_at": "document_end"
    }
  ],
  "content_security_policy": "default-src 'self'"
}