Examine source code of CENNZnet extension

{
  "author": "polkadot.{js}",
  "description": "Manage your CENNZnet accounts outside of dapps. Injects the accounts and allows signing transactions for a specific account.",
  "homepage_url": "https://github.com/cennznet/extension",
  "name": "CENNZnet extension",
  "short_name": "CENNZnet",
  "manifest_version": 2,
  "permissions": [
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_title": "CENNZnet",
    "default_popup": "index.html"
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "64": "images/icon-64.png",
    "128": "images/icon-128.png"
  },
  "web_accessible_resources": [
    "page.js"
  ],
  "content_security_policy": "script-src 'self' blob: 'unsafe-eval' 'wasm-eval'; object-src 'self'",
  "version": "0.37.3"
}