Examine source code of Karaoke Pitch

{
  "manifest_version": 3,
  "name": "Karaoke Pitch",
  "version": "0.2.0",
  "description": "Shift a YouTube video's pitch up or down without changing tempo, to make karaoke songs easier to sing.",
  "icons": {
    "32": "icons/icon.svg",
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "karaoke-pitch@davidjeastman.com",
      "strict_min_version": "120.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {}
  },
  "permissions": [
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "Karaoke Pitch",
    "default_icon": "icons/icon-disabled.svg",
    "default_area": "navbar"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "panel.css"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "soundtouch-processor.js"
      ],
      "matches": [
        "*://*.youtube.com/*",
        "*://youtube.com/*"
      ]
    }
  ]
}