Update confirm_trade_entry to support "side" parameter

freqtrade/templates/subtemplates/strategy_methods_advanced.j2

@@ -80,9 +80,10 @@ def custom_sell(self, pair: str, trade: 'Trade', current_time: 'datetime', curre
     return None
 
 def confirm_trade_entry(self, pair: str, order_type: str, amount: float, rate: float,
-                        time_in_force: str, current_time: 'datetime', **kwargs) -> bool:
+                        time_in_force: str, current_time: datetime,
+                        side: str, **kwargs) -> bool:
     """
-    Called right before placing a buy order.
+    Called right before placing a entry order.
     Timing for this function is critical, so avoid doing heavy computations or
     network requests in this method.
 
@@ -90,12 +91,13 @@ def confirm_trade_entry(self, pair: str, order_type: str, amount: float, rate: f
 
     When not implemented by a strategy, returns True (always confirming).
 
-    :param pair: Pair that's about to be bought.
+    :param pair: Pair that's about to be bought/shorted.
     :param order_type: Order type (as configured in order_types). usually limit or market.
     :param amount: Amount in target (quote) currency that's going to be traded.
     :param rate: Rate that's going to be used when using limit orders
     :param time_in_force: Time in force. Defaults to GTC (Good-til-cancelled).
     :param current_time: datetime object, containing the current datetime
+    :param side: 'long' or 'short' - indicating the direction of the proposed trade
     :param **kwargs: Ensure to keep this here so updates to this won't break your strategy.
     :return bool: When True is returned, then the buy-order is placed on the exchange.
         False aborts the process