Examine source code of Virtual Dog Pet

{
  "manifest_version": 2,
  "name": "Virtual Dog Pet",
  "short_name": "Dog Pet",
  "version": "1.0.0",
  "description": "A virtual dog companion that lives in your browser toolbar. Feed, play, and take care of your digital pet!",
  "applications": {
    "gecko": {
      "id": "webpet@trinhnv1205.github.io",
      "strict_min_version": "58.0"
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "notifications",
    "alarms"
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ],
    "persistent": true
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "128": "icons/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "icons/dog_pixel_art/dog_eating_8x8.png",
    "icons/dog_pixel_art/dog_running_8x8.png",
    "icons/dog_pixel_art/dog_sitting_8x8.png",
    "icons/dog_pixel_art/dog_standing_8x8.png",
    "icons/dog_pixel_art/eating/dog_eating_8x8_frame1.png",
    "icons/dog_pixel_art/eating/dog_eating_8x8_frame2.png",
    "icons/dog_pixel_art/eating/dog_eating_8x8_frame3.png",
    "icons/dog_pixel_art/eating/dog_eating_8x8_frame4.png",
    "icons/dog_pixel_art/running/dog_running_8x8_frame1.png",
    "icons/dog_pixel_art/running/dog_running_8x8_frame2.png",
    "icons/dog_pixel_art/running/dog_running_8x8_frame3.png",
    "icons/dog_pixel_art/running/dog_running_8x8_frame4.png",
    "icons/dog_pixel_art/sitting/dog_sitting_8x8_frame1.png",
    "icons/dog_pixel_art/sitting/dog_sitting_8x8_frame2.png",
    "icons/dog_pixel_art/sitting/dog_sitting_8x8_frame3.png",
    "icons/dog_pixel_art/sitting/dog_sitting_8x8_frame4.png",
    "icons/dog_pixel_art/standing/dog_standing_8x8_frame1.png",
    "icons/dog_pixel_art/standing/dog_standing_8x8_frame2.png",
    "icons/dog_pixel_art/standing/dog_standing_8x8_frame3.png",
    "icons/dog_pixel_art/standing/dog_standing_8x8_frame4.png"
  ]
}