feat: add FRED economic data API from St. Louis Fed

README.md

@@ -505,6 +505,7 @@ API | Description | Auth | HTTPS | CORS |
 | [apilayer marketstack](https://marketstack.com/) | Real-Time, Intraday & Historical Market Data API | `apiKey` | Yes | Unknown |
 | [Banco do Brasil](https://developers.bb.com.br/home) | All Banco do Brasil financial transaction APIs | `OAuth` | Yes | Yes |
 | [Financial Modeling Prep](https://financialmodelingprep.com/developer/docs/) | Realtime and historical stock data | `apiKey` | Yes | Unknown |
+| [FRED](https://fred.stlouisfed.org/docs/api/fred/) | Economic data from the Federal Reserve Bank of St. Louis | `apiKey` | Yes | Yes |
 | [Hotstoks](https://hotstoks.com?utm_source=public-apis) | Stock market data powered by SQL | `apiKey` | Yes | Yes |
 | [IEX Cloud](https://iexcloud.io/docs/api/) | Realtime & Historical Stock and Market Data | `apiKey` | Yes | Yes |
 | [IG](https://labs.ig.com/gettingstarted) | Spreadbetting and CFD Market Data | `apiKey` | Yes | Unknown |