[Spec] output_shape for ConvTranspose should not have batch and chann…

…els (onnx#5400)

### Description
<!-- - Describe your changes. -->
Add a sentence to highlight that output_shape for ConvTranspose should
not have batch and channels.

### Motivation and Context
<!-- - Why is this change required? What problem does it solve? -->
<!-- - If it fixes an open issue, please link to the issue here. -->
It's quite confusing that whether output_shape needs to be fully
provided. For instance, onnx#1437. An
explicit description should help prevent confusion.

cc @satyajandhyala

---------

Signed-off-by: Chun-Wei Chen <[email protected]>

docs/Changelog.md

@@ -10777,7 +10777,7 @@ This version of the operator has been available since version 11 of the default
 <dt><tt>output_padding</tt> : list of ints</dt>
 <dd>Additional elements added to the side with higher coordinate indices in the output. Each padding value in "output_padding" must be less than the corresponding stride/dilation dimension. By default, this attribute is a zero vector. Note that this attribute doesn't directly affect the computed output values. It only controls the selection of the computed values, so changing this attribute only adds or removes output elements. If "output_shape" is explicitly provided, "output_padding" does not contribute additional size to "output_shape" but participates in the computation of the needed padding amount. This is also called adjs or adjustment in some frameworks.</dd>
 <dt><tt>output_shape</tt> : list of ints</dt>
-<dd>The shape of the output can be explicitly set which will cause pads values to be auto generated. If output_shape is specified pads values are ignored. See doc for details for equations to generate pads</dd>
+<dd>The shape of the output can be explicitly set which will cause pads values to be auto generated. If output_shape is specified pads values are ignored. See doc for details for equations to generate pads. Note that the output_shape attribute value should not include dimensions for batch size and channels, which are automatically inferred.</dd>
 <dt><tt>pads</tt> : list of ints</dt>
 <dd>Padding for the beginning and ending along each spatial axis, it can take any value greater than or equal to 0. The value represent the number of pixels added to the beginning and end part of the corresponding axis. `pads` format should be as follow [x1_begin, x2_begin...x1_end, x2_end,...], where xi_begin the number of pixels added at the beginning of axis `i` and xi_end, the number of pixels added at the end of axis `i`. This attribute cannot be used simultaneously with auto_pad attribute. If not present, the padding defaults to 0 along start and end of each spatial axis.</dd>
 <dt><tt>strides</tt> : list of ints</dt>

docs/Operators.md

@@ -5677,7 +5677,7 @@ Other versions of this operator: <a href="Changelog.md#ConvTranspose-1">1</a>
 <dt><tt>output_padding</tt> : list of ints</dt>
 <dd>Additional elements added to the side with higher coordinate indices in the output. Each padding value in "output_padding" must be less than the corresponding stride/dilation dimension. By default, this attribute is a zero vector. Note that this attribute doesn't directly affect the computed output values. It only controls the selection of the computed values, so changing this attribute only adds or removes output elements. If "output_shape" is explicitly provided, "output_padding" does not contribute additional size to "output_shape" but participates in the computation of the needed padding amount. This is also called adjs or adjustment in some frameworks.</dd>
 <dt><tt>output_shape</tt> : list of ints</dt>
-<dd>The shape of the output can be explicitly set which will cause pads values to be auto generated. If output_shape is specified pads values are ignored. See doc for details for equations to generate pads</dd>
+<dd>The shape of the output can be explicitly set which will cause pads values to be auto generated. If output_shape is specified pads values are ignored. See doc for details for equations to generate pads. Note that the output_shape attribute value should not include dimensions for batch size and channels, which are automatically inferred.</dd>
 <dt><tt>pads</tt> : list of ints</dt>
 <dd>Padding for the beginning and ending along each spatial axis, it can take any value greater than or equal to 0. The value represent the number of pixels added to the beginning and end part of the corresponding axis. `pads` format should be as follow [x1_begin, x2_begin...x1_end, x2_end,...], where xi_begin the number of pixels added at the beginning of axis `i` and xi_end, the number of pixels added at the end of axis `i`. This attribute cannot be used simultaneously with auto_pad attribute. If not present, the padding defaults to 0 along start and end of each spatial axis.</dd>
 <dt><tt>strides</tt> : list of ints</dt>

onnx/defs/nn/defs.cc

@@ -1333,7 +1333,8 @@ output_shape can also be explicitly specified in which case pads values are auto
     schema.Attr(
         "output_shape",
         "The shape of the output can be explicitly set which will cause pads values to be auto generated. If output_shape is specified "
-        "pads values are ignored. See doc for details for equations to generate pads",
+        "pads values are ignored. See doc for details for equations to generate pads. Note that the output_shape attribute value "
+        "should not include dimensions for batch size and channels, which are automatically inferred.",
         AttributeProto::INTS,
         OPTIONAL_VALUE);
     schema.Attr(