Examine source code of Simple Label Editor

{
  "manifest_version": 2,
  "name": "Simple Label Editor",
  "version": "1.0",
  "description": "Rename the current tab title temporarily for easy identification.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d69d42f0-7b36-447e-98b2-c2e25a767eb1}",
      "strict_min_version": "112.0"
    }
  },
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_title": "Simple Label Editor",
    "default_popup": "popup.html",
    "default_icon": {
      "64": "icon64.png",
      "128": "icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}