Examine source code of Container Titler

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius/container-titler",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "128": "icon.png"
  },
  "manifest_version": 2,
  "name": "Container Titler",
  "permissions": [
    "contextualIdentities"
  ],
  "version": "1.0.4",
  "browser_specific_settings": {
    "gecko": {
      "id": "{90dd7337-a8a2-4bd7-b1cc-aef7c3baf901}"
    }
  }
}