Update readme

Author: MDUYN

README.md

@@ -16,7 +16,7 @@ pip install finterion
 ## Usage
 Example usage
 ```python
-from finterion import Finterion, OrderStatus
+from finterion import Finterion, OrderStatus, OrderSide, OrderType
 
 # Create a client and configure it with your algorithm api keys from ELTYER
 client = Finterion(api_key="<YOUR_API_KEY>")
@@ -36,14 +36,18 @@ market_order = client.create_market_order(
 )
 
 # Get positions
-positions = client.get_positions()
-position = client.get_position("btc")
+positions = client.get_positions(symbol="btc")
+position = client.get_position(positions[0].id)
 
 # Get orders
 orders = client.get_orders()
 orders = client.get_orders(
-    target_symbol="btc", status=OrderStatus.PENDING.value
+    target_symbol="btc", 
+    status=OrderStatus.PENDING,
+    order_type=OrderType.LIMIT,
+    order_side=OrderSide.BUY
 )
+order = client.get_order(orders[0].id)
 
 # Get the portfolio
 portfolio = client.get_portfolio()