SoftSign-9 specification (#10690)

* SoftSign-9 specification

* opset9 update

* fix formula

* comments resolving

docs/OV_Runtime_UG/Operations_specifications.md

@@ -177,6 +177,7 @@
    openvino_docs_ops_activation_SoftMax_1
    openvino_docs_ops_activation_SoftMax_8
    openvino_docs_ops_activation_SoftPlus_4
+   openvino_docs_ops_activation_SoftSign_9
    openvino_docs_ops_movement_SpaceToBatch_2
    openvino_docs_ops_movement_SpaceToDepth_1
    openvino_docs_ops_movement_Split_1

docs/ops/activation/SoftSign_9.md

@@ -0,0 +1,48 @@
+# SoftSign {#openvino_docs_ops_activation_SoftSign_9}
+
+**Versioned name**: *SoftSign-9*
+
+**Category**: *Activation function*
+
+**Short description**: *SoftSign* performs element-wise activation on a given input tensor.
+
+**Detailed description**: 
+
+*SoftSign* operation is introduced in this [article](https://arxiv.org/abs/2010.09458).
+
+*SoftSign Activation Function* is a neuron activation function based on the mathematical function:
+
+\f[
+SoftSign(x) = \frac{x}{1+|x|}
+\f]
+
+**Inputs**:
+
+* **1**: `data`. Input tensor of type *T*
+
+**Outputs**:
+
+* **1**: The resulting tensor of the same shape and type as the input tensor.
+
+**Types**:
+
+* **T**: Arbitrary supported floating-point type.
+
+**Example**
+
+```xml
+<layer ... type="SoftSign">
+    <input>
+        <port id="0">
+            <dim>256</dim>
+            <dim>56</dim>
+        </port>
+    </input>
+    <output>
+        <port id="1">
+            <dim>256</dim>
+            <dim>56</dim>
+        </port>
+    </output>
+</layer>
+```

docs/ops/opset9.md

@@ -161,6 +161,7 @@ declared in `namespace opset9`.
 * [Slice](movement/Slice_8.md)
 * [SoftMax](activation/SoftMax_8.md)
 * [SoftPlus](activation/SoftPlus_4.md)
+* [SoftSign](activation/SoftSign_9.md)
 * [SpaceToBatch](movement/SpaceToBatch_2.md)
 * [SpaceToDepth](movement/SpaceToDepth_1.md)
 * [Split](movement/Split_1.md)