Examine source code of Derive Suburbane new tab

{
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "homepage_url": "https://realrecordzlab.github.io/",
  "description": "__MSG_extDesc__",
  "default_locale": "it",
  "permissions": [
    "https://*.duckduckgo.com/*",
    "https://realrecordzlab.herokuapp.com/platform/api/*",
    "https://derivesuburbane.it/*",
    "browsingData",
    "history",
    "topSites",
    "tabs"
  ],
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ],
    "persistent": false
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "version": "1.0.0",
  "content_security_policy": "script-src 'self' ; object-src 'self'"
}