Examine source code of YNAB Date Borders

{
  "manifest_version": 2,
  "name": "YNAB Date Borders",
  "version": "1.1",
  "description": "Adds a border at top to rows on YNAB to help view transactions with different dates easily",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://app.ynab.com/*"
      ],
      "js": [
        "ynab-date-borders.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bb1c2507-602a-4c14-9196-446973d816b7}"
    }
  }
}