Examine source code of Universal Video Skip

{
  "manifest_version": 2,
  "name": "Universal Video Skip",
  "version": "1.0",
  "description": "Skip forward in videos with double-click or S key, works on all websites including mobile",
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Video Skip Settings",
    "default_icon": {
      "32": "icons/icon.png"
    }
  },
  "icons": {
    "32": "icons/icon.png"
  },
  "web_accessible_resources": [
    "injected.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7c2a16ee-29d3-4b8a-9df5-29140ae5366f}"
    }
  }
}