Examine source code of Accessible Shortcuts

{
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "version": "2.2.0",
  "description": "__MSG_appDescription__",
  "default_locale": "pt_BR",
  "browser_specific_settings": {
    "gecko": {
      "id": "{d51ec0d3-bafe-4824-b7d7-f22112001c81}"
    }
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage",
    "tabs",
    "webNavigation",
    "clipboardRead",
    "contextMenus"
  ],
  "web_accessible_resources": [
    "*.wav",
    "*.js",
    "*.css",
    "*.json",
    "*.jpg"
  ],
  "icons": {
    "128": "assets/images/icon-128.png"
  },
  "action": {
    "default_popup": "default.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "assets/js/main.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "assets/js/background.js"
    ]
  }
}