DOC: added use of end_date & start_date in live mode.

issues #225 & #213

docs/source/live-trading.rst

@@ -176,6 +176,13 @@ Here is the breakdown of the new arguments:
 - ``simulate_orders``: Enables the paper trading mode, in which orders are
   simulated in Catalyst instead of processed on the exchange. It defaults to 
   ``True``.
+- ``end_date``: When setting the end_date to a time in the **future**,
+  it will schedule the live algo to finish gracefully at the specified date.
+- ``start_date``: (**Will be implemented in the future**)
+  The live algo starts by default in the present, as mentioned above.
+  by setting the start_date to a time in the future, the algorithm would
+  essentially sleep and when the predefined time comes, it would start executing.
+
 
 Here is a complete algorithm for reference:
 `Buy Low and Sell High <https://github.com/enigmampc/catalyst/blob/master/catalyst/examples/buy_low_sell_high_live.py>`_