Examine source code of Coding Dynamic theme

{
  "description": "Shows a new theme every hour. The theme is related to coding.",
  "homepage_url": "https://github.com/nabendu82/DynamicCodingTheme",
  "icons": {
    "48": "icons/logo_48.png",
    "64": "icons/logo_64.png"
  },
  "manifest_version": 2,
  "name": "Coding Dynamic theme",
  "permissions": [
    "alarms",
    "theme"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "version": "2.1resigned1",
  "applications": {
    "gecko": {
      "strict_min_version": "55.0a2",
      "id": "{af0cc797-c53e-4c65-a6eb-64ce6feeeae4}"
    }
  }
}