Examine source code of Genei: Ctrl+F but better

{
  "manifest_version": 2,
  "name": "Genei Browser Extension",
  "version": "0.1",
  "description": "Summarise any webpage instantly while you browse!",
  "icons": {
    "16": "logo_primary_16.png",
    "48": "logo_primary_48.png",
    "128": "logo_primary_128.png"
  },
  "content_security_policy": "script-src 'self' https://ssl.google-analytics.com; object-src 'self'",
  "browser_action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.google.com/"
      ],
      "css": [
        "/static/css/index.css"
      ],
      "js": [
        "/static/js/index.js"
      ]
    }
  ],
  "permissions": [
    "contextMenus",
    "tabs",
    "https://*/*"
  ]
}