update perf interface (#72)

* update perf interface

* remove old ping interface in platofrm

content/docs/platform/specifications/mqtt-panduza/interfaces/perf.md

@@ -0,0 +1,41 @@
+---
+title: "Perf"
+weight: 300
+---
+
+This document describes the specific attributes of Perf interfaces.
+
+Please refer to [API interface](/docs/mqtt/core.md) to get a generic description of the interface mechanism.
+
+The goal of the perf interface is to provide a way to test performance of the chain client/network/broker/platform.
+
+## Info
+
+```json
+{
+    "type": "perf",
+    "version": "0.0.0"
+}
+```
+
+### Changelog
+
+#### Version 0.0
+
+- Experimentations
+
+## Attributes
+
+| Attribute name | Retain Topic |
+| :------------: | :----------: |
+|    ping        |     True     |
+
+### `[PLATF_00000_00]` - Attribute 'ping'
+
+This attribute **must** have the following fields:
+
+| Field name |            Description             | Default | Type  | Read-only |
+| :--------- | :--------------------------------: | :-----: | :---: | :-------: |
+| value      | Contains the value set by the user |    0    | bytes |   False   |
+
+This attribute just set back the value.

content/docs/platform/specifications/mqtt-panduza/interfaces/platform.md

@@ -99,18 +99,4 @@ Store structure
 }
 ```
 
-### `[PLATF_REQ_ITF_PLATFORM_0120_00]` - Attribute 'ping'
-
-The goal of the ping attribute is to provide a way to test performance of the chain client/network/broker/platform.
-
-This attribute **must** have the following fields:
-
-| Field name |                         Description                          | Default |  Type   | Read-only |
-| :--------- | :----------------------------------------------------------: | :-----: | :-----: | :-------: |
-| value      |     Contains the value set by the user                       |  0      | integer |   False   |
-
-When a client wants to start a perf test, he send 1 and wait for answer, then 2, then 3... the goal is to measure the number of iteration in 1 seconde.
-
-
-