Examine source code of New Word Tab

{
  "manifest_version": 2,
  "name": "New Word Tab",
  "description": "Learn a word per new tab",
  "version": "1.5.0",
  "chrome_url_overrides": {
    "newtab": "./dist/newTab/index.html"
  },
  "options_ui": {
    "page": "./dist/options/index.html",
    "open_in_tab": true,
    "chrome_style": false,
    "browser_style": false
  },
  "icons": {
    "16": "./assets/16.png",
    "32": "./assets/32.png",
    "48": "./assets/48.png",
    "128": "./assets/128.png"
  },
  "content_security_policy": "object-src 'self'; script-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{b148b3e9-5597-4692-9afe-6071139924e6}"
    }
  }
}