Examine source code of M3Q – Audio Equalizer

{
  "manifest_version": 3,
  "name": "M3Q",
  "version": "1.0.25",
  "description": "Simple audio equalizer for any tab and any website.",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "shared/shared.js",
      "firefox/core.js"
    ]
  },
  "action": {
    "default_title": "M3Q",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "browser-polyfill.min.js",
        "shared/shared.js",
        "shared/content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "m3q@local.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}