Examine source code of Readabler – Web Accessibility Toolbar

{
  "manifest_version": 3,
  "name": "Readabler – Web Accessibility Toolbar",
  "short_name": "Readabler",
  "description": "Read any website your way — fonts, contrast, spacing, reading masks and six accessibility profiles, on every page you open.",
  "version": "1.0.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "readabler@readabler.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "action": {
    "default_popup": "index.html",
    "default_title": "Readabler — accessibility adjustments",
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    }
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "background": {
    "scripts": [
      "assets/js/background.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "assets/js/content.js"
      ],
      "css": [
        "assets/css/content.css"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "api/core/v1/fonts/*",
        "images/cursors/*"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "storage",
    "cookies",
    "alarms"
  ],
  "commands": {
    "_execute_action": {
      "suggested_key": {
        "default": "Alt+A"
      },
      "description": "Open the Readabler panel"
    }
  },
  "host_permissions": [
    "https://account.readabler.com/*",
    "https://dev.readabler.com/*"
  ]
}