Examine source code of Theme Day and Night

{
  "description": "Theme day and night",
  "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/dynamic-theme",
  "manifest_version": 2,
  "name": "Theme Day and Night",
  "permissions": [
    "alarms",
    "theme"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "55.0a2",
      "id": "{e358e7b4-3527-42d5-ba88-9b8e98d8000d}"
    }
  }
}