feat(taapi): add get_stocks method to retrieve supported stocks

paperone/taapi.py

@@ -78,6 +78,24 @@ class TaapiClient:
 
         return self._session.get(url, params=params, timeout=timeout)
 
+    def get_available_tickers(self) -> list[str] | None:
+        """
+        Retrieves a list of supported stocks from the TAAPI API.
+        """
+        target_url = f"{self._base_url}/exchange-symbols"
+
+        params: dict[str, str | int | bool] = {
+            "secret": self._api_key,
+            "type": "stocks",
+        }
+
+        response = self._do_get(target_url, params)
+
+        if response.status_code != 200:
+            return None
+
+        return list(response.json())
+
     def query_indicator(
         self,
         ticker: str,