Examine source code of Localhost Tab Label

{
  "manifest_version": 2,
  "name": "Localhost Tab Label",
  "description": "Adds a configurable prefix to the page title for tabs that have localhost pages loaded.",
  "version": "0.9.0",
  "author": "Andrew Heiss",
  "homepage_url": "https://github.com/andrewheiss/localhost-tab-label",
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://localhost/*",
        "*://127.0.0.1/*",
        "*://0.0.0.0/*",
        "*://*.local/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "localhost-tab-label@andrewheiss.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}