Examine source code of Return YouTube Live Subscriptions

{
  "manifest_version": 2,
  "name": "Return YouTube Live Subscriptions",
  "description": "See which YouTube channels you subscribe to are live right now.",
  "version": "0.2.0",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Return YouTube Live Subscriptions",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "https://www.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "youtube-sidebar.js",
        "youtube-channel-scraper.js"
      ],
      "css": [
        "youtube-sidebar.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "return-yt-live-subscriptions@tsherlock.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}