remove gridIn mentions

Author: jordan-smith721

source/motor-async-migration.txt

@@ -60,10 +60,7 @@ Method Signature Changes
 
 The following Motor method signatures behave differently in the {+driver-async+} driver:
 
-- ``GridOut.open()`` returns ``None``.
 - ``AsyncMongoClient.__init__()`` does not accept an ``io_loop`` parameter.
-- ``GridIn.set()`` does not accept a filename. Instead pass a file name by using the
-  ``GridIn.filename`` attribute.
 - ``AsyncCursor.each()`` does not exist in the {+driver-async+} driver.
 - ``MotorGridOut.stream_to_handler()`` does not exist in the {+driver-async+} driver.
 - ``AsyncCursor.to_list(0)`` is not valid in the {+driver-async+} driver. Use