Examine source code of Tab Volume Control

{
  "manifest_version": 2,
  "name": "Tab Volume Control",
  "version": "1.0.0",
  "description": "Control volume levels for individual tabs with volume lock to prevent website hijacking and auto-leveling to normalize loud/quiet audio",
  "homepage_url": "https://github.com/yourusername/firefox-tab-volume-control",
  "icons": {
    "48": "icons/volume-48.png",
    "96": "icons/volume-96.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-volume-control@example.com",
      "strict_min_version": "91.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/volume-19.png",
      "38": "icons/volume-38.png"
    },
    "default_title": "Tab Volume Control",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ]
}