Add HSigmoid spec (#2412)

* Add HSigmoid spec

docs/doxygen/ie_docs.xml

@@ -160,6 +160,7 @@
                         <tab type="user" title="GroupConvolutionBackpropData-1" url="@ref openvino_docs_ops_convolution_GroupConvolutionBackpropData_1"/>
                         <tab type="user" title="GroupConvolution-1" url="@ref openvino_docs_ops_convolution_GroupConvolution_1"/>
                         <tab type="user" title="HardSigmoid-1" url="@ref openvino_docs_ops_activation_HardSigmoid_1"/>
+                        <tab type="user" title="HSigmoid-5" url="@ref openvino_docs_ops_activation_HSigmoid_5"/>
                         <tab type="user" title="HSwish-4" url="@ref openvino_docs_ops_activation_HSwish_4"/>
                         <tab type="user" title="Interpolate-1" url="@ref openvino_docs_ops_image_Interpolate_1"/>
                         <tab type="user" title="Interpolate-4" url="@ref openvino_docs_ops_image_Interpolate_4"/>

docs/ops/activation/HSigmoid_5.md

@@ -0,0 +1,47 @@
+## HSigmoid<a name="HSigmoid"></a> {#openvino_docs_ops_activation_HSigmoid_5}
+
+**Versioned name**: *HSigmoid-5*
+
+**Category**: *Activation function*
+
+**Short description**: HSigmoid takes one input tensor and produces output tensor where the hard version of sigmoid function is applied to the tensor elementwise.
+
+**Detailed description**: For each element from the input tensor calculates corresponding
+element in the output tensor with the following formula: 
+
+    \f[
+    HSigmoid(x) = \frac{min(max(x + 3, 0), 6)}{6}
+    \f]
+
+The HSigmoid operation is introduced in the following [article](https://arxiv.org/pdf/1905.02244.pdf).
+
+**Attributes**: operations has no attributes.
+
+**Inputs**:
+
+* **1**: A tensor of type *T*. **Required.**
+
+**Outputs**:
+
+* **1**: The resulting tensor of the same shape and type as input tensor.
+
+**Types**
+
+* *T*: any floating point type.
+
+**Examples**
+
+```xml
+<layer ... type="HSigmoid">
+    <input>
+        <port id="0">
+            <dim>256</dim>
+        </port>
+    </input>
+    <output>
+        <port id="1">
+            <dim>256</dim>
+        </port>
+    </output>
+</layer>
+```

docs/ops/opset5.md

@@ -65,6 +65,7 @@ declared in `namespace opset5`.
 * [GRUCell](sequence/GRUCell_3.md)
 * [GRUSequence](sequence/GRUSequence_5.md)
 * [HardSigmoid](activation/HardSigmoid_1.md)
+* [HSigmoid](activation/HSigmoid_5.md)
 * [HSwish](activation/HSwish_4.md)
 * [Interpolate](image/Interpolate_4.md)
 * [Less](comparison/Less_1.md)