Examine source code of FocusRead

{
  "manifest_version": 3,
  "name": "FocusRead",
  "description": "Accessible, distraction-free reading mode.",
  "version": "1.0.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "focusread@riakvolk",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "commands",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "action": {
    "default_title": "FocusRead",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "options_page": "options.html",
  "commands": {
    "toggle-reading-mode": {
      "suggested_key": {
        "default": "Ctrl+Shift+R"
      },
      "description": "Toggle Reading Mode"
    }
  }
}