Examine source code of Rate That Site

{
  "manifest_version": 3,
  "name": "Rate That Site",
  "version": "2.2",
  "description": "Rate web pages with an emoji, and see how others reacted.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{c4bc3ec9-2b58-4304-a945-3fffe8f44acd}"
    }
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "action": {
    "default_popup": "src/popup/popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://*/*"
      ],
      "js": [
        "src/inject.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "src/tab-listener.js"
    ]
  },
  "icons": {
    "48": "src/icons/85.png",
    "96": "src/icons/85.png"
  }
}