Remove Thread-protocol from README (#2383)

Author: Arto Kinnunen

README.md

@@ -3,37 +3,29 @@ ARM Mesh networking stack
 
 This repository contains the ARM mesh networking stack that  provides support for the following mesh protocols:
 
-  * 6LoWPAN with Neighbor Discovery (ND) and Mesh Link Establishment (MLE)
-  * Thread
-  * Wi-SUN
+* 6LoWPAN with Neighbor Discovery (ND) and Mesh Link Establishment (MLE)
+* Wi-SUN
 
- All networking stacks are using IEEE 802.15.4 based radios.
+All networking stacks are using IEEE 802.15.4 based radios.
 
 The full documentation is hosted in [Mbed OS documentation](https://os.mbed.com/docs/mbed-os/latest/reference/mesh-tech.html).
 
-On mbed OS, mesh networking stacks can be used  through [Mbed Mesh API](https://os.mbed.com/docs/mbed-os/latest/apis/mesh-api.html) and [Network Socket API](https://os.mbed.com/docs/mbed-os/v5.11/apis/network-socket.html).
+On mbed OS, mesh networking stacks can be used  through [Mbed Mesh API](https://os.mbed.com/docs/mbed-os/latest/apis/mesh-api.html) and [Network Socket API](https://os.mbed.com/docs/mbed-os/latest/apis/network-socket.html).
 
 To see, how the mesh networking stack works, check the example application [mbed-os-example-mesh-minimal](https://github.com/ARMmbed/mbed-os-example-mesh-minimal).
 
-  
-##6LoWPAN with ND and MLE
+
+## 6LoWPAN with ND and MLE
 
 This networking stack is using standard 6LoWPAN and uses:
 
 * Neighbor Discovery Protocol ([RFC4861](https://tools.ietf.org/html/rfc4861)) to locate other devices in the mesh network. 
 * Mesh-Link-Establishment ([draft-kelsey-intarea-mesh-link-establishment-06](https://tools.ietf.org/html/draft-kelsey-intarea-mesh-link-establishment-06)) is used for establishing and configuring secure radio links. 
-  
-##Thread
-Thread is standardized by [Thread group](https://www.threadgroup.org/).
-
-![](docs/img/thread_certified.png)
 
-mbed OS is now a Thread Certified Component. Using IPv6 with 6LoWPAN as the foundation, Thread technology provides a low-power, self-healing mesh network designed for the home.
 
-##Wi-SUN
+## Wi-SUN
 Wi-SUN (Smart Utility Networks) specification is standardized by [Wi-SUN Alliance](https://www.wi-sun.org/). 
 
-Mbed OS release 5.12 contains the initial Mbed Wi-SUN FAN implementation. Functionality of the Mbed Wi-SUN network stack will be updated when the Wi-SUN protocol is specified further.
 
 ## License