closed caption - dual subtitle viewer

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "__MSG_name__",
  "manifest_version": 3,
  "version": "2.8.0",
  "description": "__MSG_description__",
  "default_locale": "en",
  "background": {
    "service_worker": "background.js"
  },
  "permissions": [
    "storage",
    "commands"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/kitty-16.png",
      "32": "assets/kitty-32.png"
    }
  },
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+P",
        "mac": "Command+Shift+P"
      }
    },
    "active-translate": {
      "suggested_key": {
        "default": "Ctrl+Shift+K",
        "mac": "Command+Shift+K"
      },
      "description": "Toggle translate"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://frontendmasters.com/*",
        "*://www.udemy.com/*",
        "*://www.youtube.com/*",
        "*://epicreact.dev/*",
        "*://www.ted.com/*",
        "*://www.netflix.com/*",
        "*://threejs-journey.com/*",
        "*://start.ru/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "assets/kitty-16.png",
    "32": "assets/kitty-32.png",
    "48": "assets/kitty-48.png",
    "128": "assets/kitty-128.png"
  }
}