feat: add alpaca provider

config/alpaca.php

@@ -0,0 +1,8 @@
+<?php
+
+declare(strict_types=1);
+
+return [
+    'key' => env('ALPACA_API_KEY'),
+    'secret' => env('ALPACA_API_SECRET'),
+];

config/investbrain.php

@@ -11,6 +11,7 @@ return [
     'interfaces' => [
         'yahoo' => App\Interfaces\MarketData\YahooMarketData::class,
         'alphavantage' => App\Interfaces\MarketData\AlphaVantageMarketData::class,
+        'alpaca' => App\Interfaces\MarketData\AlpacaMarketData::class,
         'finnhub' => App\Interfaces\MarketData\FinnhubMarketData::class,
         'fake' => App\Interfaces\MarketData\FakeMarketData::class,
     ],