Examine source code of XaCi-leads

{
  "manifest_version": 3,
  "version": "0.0.0.1",
  "name": "XaCi-leads",
  "description": "A tool to easy save urls in different categories",
  "action": {
    "default_popup": "index.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "xacileads@example.com",
      "strict_min_version": "42.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "permissions": [
    "tabs"
  ]
}