Examine source code of Text Direction Togglers

{
  "manifest_version": 2,
  "name": "Text Direction Toggler",
  "version": "1.0",
  "description": "Toggle webpage text direction (LTR/RTL) with a single click.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{16a9f6b7-aa35-428e-bd78-ecfad2dc5b37}"
    }
  }
}