foo doc and tutorial (apache#6708)

Renamed a bunch of APIs:
Layer.forward -> Layer.call
Layer.generic_forward -> Layer.forward
Layer.scope -> Layer.name_scope()

Removed Layer.ndarray_forward and Layer.symbol_forward.

Added tutorial and re-aranged docs.

docs/api/python/foo.md

@@ -1,4 +1,4 @@
-# Foo API
+# Foo Package
 
 ```eval_rst
 .. currentmodule:: mxnet.foo
@@ -8,7 +8,18 @@
 .. warning:: This package is currently experimental and may change in the near future.
 ```
 
-## API Reference
+## Overview
+
+Foo package is a high-level interface for MXNet designed to be easy to use while
+keeping most of the flexibility of low level API. Foo supports both imperative
+and symbolic programming, making it easy to train complex models imperatively
+in Python and then deploy with symbolic graph in C++ and Scala.
+
+## Parameter
+
+```eval_rst
+.. currentmodule:: mxnet.foo
+```
 
 <script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
 
@@ -17,8 +28,192 @@
     :members:
 .. autoclass:: mxnet.foo.ParameterDict
     :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+
+## Neural Network Layers
+
+```eval_rst
+.. currentmodule:: mxnet.foo.nn
+```
+
+### Containers
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. currentmodule:: mxnet.foo.nn
+.. autoclass:: mxnet.foo.nn.Layer
+    :members:
+
+    .. automethod:: __call__
+.. autoclass:: mxnet.foo.nn.Sequential
+    :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+### Basic Layers
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. currentmodule:: mxnet.foo.nn  
+.. autoclass:: mxnet.foo.nn.Dense
+    :members:
+.. autoclass:: mxnet.foo.nn.Activation
+    :members:
+.. autoclass:: mxnet.foo.nn.Dropout
+    :members:
+.. autoclass:: mxnet.foo.nn.BatchNorm
+    :members:
+.. autoclass:: mxnet.foo.nn.LeakyReLU
+    :members:
+.. autoclass:: mxnet.foo.nn.Embedding
+    :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+### Convolutional Layers
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. currentmodule:: mxnet.foo.nn  
+.. autoclass:: mxnet.foo.nn.Conv1D
+    :members:
+.. autoclass:: mxnet.foo.nn.Conv2D
+    :members:
+.. autoclass:: mxnet.foo.nn.Conv3D
+    :members:
+.. autoclass:: mxnet.foo.nn.Conv1DTranspose
+    :members:
+.. autoclass:: mxnet.foo.nn.Conv2DTranspose
+    :members:
+.. autoclass:: mxnet.foo.nn.Conv3DTranspose
+    :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+
+### Pooling Layers
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. currentmodule:: mxnet.foo.nn
+.. autoclass:: mxnet.foo.nn.MaxPool1D
+    :members:
+.. autoclass:: mxnet.foo.nn.MaxPool2D
+    :members:
+.. autoclass:: mxnet.foo.nn.MaxPool3D
+    :members:
+.. autoclass:: mxnet.foo.nn.AvgPool1D
+    :members:
+.. autoclass:: mxnet.foo.nn.AvgPool2D
+    :members:
+.. autoclass:: mxnet.foo.nn.AvgPool3D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalMaxPool1D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalMaxPool2D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalMaxPool3D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalAvgPool1D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalAvgPool2D
+    :members:
+.. autoclass:: mxnet.foo.nn.GlobalAvgPool3D
+    :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+
+## Recurrent Layers
+
+```eval_rst
+.. currentmodule:: mxnet.foo.rnn
+```
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. autoclass:: mxnet.foo.rnn.RecurrentCell
+    :members:
+
+    .. automethod:: __call__
+.. autoclass:: mxnet.foo.rnn.LSTMCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.GRUCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.RNNCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.FusedRNNCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.SequentialRNNCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.BidirectionalCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.DropoutCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.ZoneoutCell
+    :members:
+.. autoclass:: mxnet.foo.rnn.ResidualCell
+    :members:
+```
+
+<script>auto_index("api-reference");</script>
+
+## Trainer
+
+```eval_rst
+.. currentmodule:: mxnet.foo
+```
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
 .. autoclass:: mxnet.foo.Trainer
     :members:
 ```
 
 <script>auto_index("api-reference");</script>
+
+## Loss functions
+
+```eval_rst
+.. currentmodule:: mxnet.foo.loss
+```
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. automethod:: mxnet.foo.loss.custom_loss
+.. automethod:: mxnet.foo.loss.multitask_loss
+.. automethod:: mxnet.foo.loss.l1_loss
+.. automethod:: mxnet.foo.loss.l2_loss
+.. automethod:: mxnet.foo.loss.softmax_cross_entropy_loss
+```
+
+<script>auto_index("api-reference");</script>
+
+## Utilities
+
+```eval_rst
+.. currentmodule:: mxnet.foo.utils
+```
+
+<script type="text/javascript" src='../../_static/js/auto_module_index.js'></script>
+
+```eval_rst
+.. automethod:: mxnet.foo.utils.split_data
+.. automethod:: mxnet.foo.utils.load_data
+```
+
+<script>auto_index("api-reference");</script>

docs/api/python/index.md

@@ -29,10 +29,6 @@ imported by running:
    symbol
    module
    foo
-   foo.nn
-   foo.rnn
-   foo.loss
-   foo.utils
    rnn
    kvstore
    io