Examine source code of MathML Font Settings

{
  "manifest_version": 2,
  "name": "MathML Font Settings",
  "version": "0.3.3resigned1",
  "description": "Add context menu items to configure MathML font settings.",
  "author": "Frédéric Wang",
  "homepage_url": "https://github.com/fred-wang/webextension-mathml-font-settings",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "default_locale": "en_US",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "contextMenus"
  ],
  "applications": {
    "gecko": {
      "id": "jid1-EQE4AIXPwNXvEA@jetpack"
    }
  }
}