Add Alpaca (#2143)

README.md

@@ -522,6 +522,7 @@ API | Description | Auth | HTTPS | CORS |
 |---|---|---|---|---|
 | [Abstract VAT Validation](https://www.abstractapi.com/vat-validation-rates-api) | Validate VAT numbers and calculate VAT rates | `apiKey` | Yes | Yes |
 | [Aletheia](https://aletheiaapi.com/) | Insider trading data, earnings call analysis, financial statements, and more | `apiKey` | Yes | Yes |
+| [Alpaca](https://alpaca.markets/docs/api-documentation/api-v2/market-data/alpaca-data-api-v2/) | Realtime and historical market data on all US equities and ETFs | `apiKey` | Yes | Yes |
 | [Alpha Vantage](https://www.alphavantage.co/) | Realtime and historical stock data | `apiKey` | Yes | Unknown |
 | [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 |