Examine source code of screen reader

{
  "name": "screen reader",
  "version": "1.0.2",
  "manifest_version": 3,
  "description": "",
  "permissions": [
    "activeTab",
    "tabs",
    "contextMenus",
    "storage",
    "<all_urls>"
  ],
  "host_permissions": [
    "*://*/*",
    "<all_urls>"
  ],
  "action": {
    "default_title": "Screen Reader",
    "default_icon": "icons/icon-gray.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "32": "icons/icon-gray.png",
    "72": "icons/icon-gray.png",
    "128": "icons/icon-gray.png",
    "512": "icons/icon-gray.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>",
        "http://*/*",
        "*://*/*"
      ],
      "css": [],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "screen-reader@majestic.com"
    }
  }
}