Examine source code of New Tab Notes

{
  "manifest_version": 2,
  "name": "Tab Notes",
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-notes@ryux",
      "strict_min_version": "60.0"
    }
  },
  "version": "0.1.2",
  "author": "Nishit",
  "icons": {
    "48": "icon48.png"
  },
  "description": "Allows you to take notes in the new tab page",
  "permissions": [
    "storage"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "Tab notes",
    "default_popup": "newtab.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Y"
      }
    }
  }
}