Examine source code of YouTube Todo

{
  "manifest_version": 2,
  "name": "YouTube Todo",
  "version": "1.1.0",
  "description": "Save the current YouTube video to your watch-later todo service.",
  "author": "YouTube Todo",
  "homepage_url": "https://www.youtube-todo.com",
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-todo@pforth.local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "authenticationInfo",
          "browsingActivity"
        ]
      }
    }
  },
  "icons": {
    "32": "icons/icon-32.svg",
    "64": "icons/icon-64.svg"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "menus",
    "notifications",
    "*://www.youtube.com/*",
    "*://m.youtube.com/*",
    "https://www.youtube-todo.com/*",
    "https://youtube-todo.com/*",
    "http://localhost/*",
    "https://localhost/*"
  ],
  "browser_action": {
    "default_title": "Save YouTube video",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/icon-32.svg",
      "64": "icons/icon-64.svg"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://m.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://www.youtube-todo.com/*",
        "https://youtube-todo.com/*",
        "http://localhost/*",
        "https://localhost/*"
      ],
      "js": [
        "detect.js"
      ],
      "run_at": "document_start"
    }
  ]
}