Examine source code of London Spitfires Theme

{
  "description": "A theme inspired by colors of London Spitfires.",
  "manifest_version": 2,
  "name": "London Spitfires Theme",
  "permissions": [
    "theme"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "version": "1.1resigned1",
  "browser_specific_settings": {
    "gecko": {
      "id": "{5f63212a-8833-4959-b213-890785e91859}"
    }
  }
}