Examine source code of Mango

{
  "manifest_version": 2,
  "name": "Mango",
  "version": "3.0",
  "description": "Obliterates rounded corners.",
  "icons": {
    "48": "img/mango-48.jpg",
    "96": "img/mango-96.jpg"
  },
  "default_icon": {
    "96": "img/mango-96.jpg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "adrianvictor.mango@disroot.org"
    }
  },
  "browser_action": {
    "default_icon": "img/mango-96.jpg",
    "default_title": "Mango",
    "default_popup": "mango.html"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "mango.js"
      ]
    }
  ]
}