Examine source code of Matrix Rain Clock

{
  "manifest_version": 2,
  "name": "Matrix Rain Clock",
  "version": "1.6.1",
  "description": "Replaces the new tab page with a Matrix Rain animation and a digital clock.",
  "chrome_url_overrides": {
    "newtab": "src/index.html"
  },
  "chrome_settings_overrides": {
    "homepage": "src/index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{58010210-b305-4f3a-aeb3-05480b0e65ad}"
    }
  },
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  }
}