Examine source code of RTL toggle

{
  "manifest_version": 2,
  "name": "Convert Text Direction",
  "version": "1.0",
  "description": "Converts text direction from left-to-right to right-to-left.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Convert Text Direction"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{113de40c-3f41-43e7-afa2-54d1260a99fb}"
    }
  }
}