update docs

Author: zsdonghao

tensorlayer/layers.py

@@ -4731,11 +4731,13 @@ def __init__(self, shape, filter_size, num_features, forget_bias=1.0, input_size
 
     @property
     def state_size(self):
+        """ State size of the LSTMStateTuple. """
         return (LSTMStateTuple(self._num_units, self._num_units)
                 if self._state_is_tuple else 2 * self._num_units)
 
     @property
     def output_size(self):
+        """ Number of units in outputs. """
         return self._num_units
 
     def __call__(self, inputs, state, scope=None):