update of api docstrings across coach and tutorials [WIP] (#91)

* updating the documentation website
* adding the built docs
* update of api docstrings across coach and tutorials 0-2
* added some missing api documentation
* New Sphinx based documentation

rl_coach/agents/nec_agent.py

@@ -43,6 +43,39 @@ class NECNetworkParameters(NetworkParameters):
 
 
 class NECAlgorithmParameters(AlgorithmParameters):
+    """
+    :param dnd_size: (int)
+        Defines the number of transitions that will be stored in each one of the DNDs. Note that the total number
+        of transitions that will be stored is dnd_size x num_actions.
+
+    :param l2_norm_added_delta: (float)
+        A small value that will be added when calculating the weight of each of the DND entries. This follows the
+        :math:`\delta` patameter defined in the paper.
+
+    :param new_value_shift_coefficient: (float)
+        In the case where a ew embedding that was added to the DND was already present, the value that will be stored
+        in the DND is a mix between the existing value and the new value. The mix rate is defined by
+        new_value_shift_coefficient.
+
+    :param number_of_knn: (int)
+        The number of neighbors that will be retrieved for each DND query.
+
+    :param DND_key_error_threshold: (float)
+        When the DND is queried for a specific embedding, this threshold will be used to determine if the embedding
+        exists in the DND, since exact matches of embeddings are very rare.
+
+    :param propagate_updates_to_DND: (bool)
+        If set to True, when the gradients of the network will be calculated, the gradients will also be
+        backpropagated through the keys of the DND. The keys will then be updated as well, as if they were regular
+        network weights.
+
+    :param n_step: (int)
+        The bootstrap length that will be used when calculating the state values to store in the DND.
+
+    :param bootstrap_total_return_from_old_policy: (bool)
+        If set to True, the bootstrap that will be used to calculate each state-action value, is the network value
+        when the state was first seen, and not the latest, most up-to-date network value.
+    """
     def __init__(self):
         super().__init__()
         self.dnd_size = 500000