Examine source code of Hotkey Hero

{
  "manifest_version": 2,
  "name": "Hotkey hero",
  "description": "Become a faster dev by learning powerful hotkeys",
  "version": "1.0.0.4",
  "permissions": [],
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "icons": {
    "128": "favicon.png"
  }
}