Fix links in thread_intro.md

Update links.

Author: Amanda Butler

docs/reference/technology/mesh/thread_intro.md

@@ -31,7 +31,7 @@ The key elements of Mbed OS are:
 - Mbed RTOS (Arm CMSIS-RTOS) providing the real time software execution.
 - Toolchain and IDE support.
 
-Mbed Thread is implemented in the Nanostack library, which also supports the 6LoWPAN protocol. In Mbed OS, the Thread stack runs in its own RTOS thread using an internal event scheduler. Mbed OS provides the [Mesh C++ API](/docs/v5.8/reference/mesh.html) for building Thread applications.
+Mbed Thread is implemented in the Nanostack library, which also supports the 6LoWPAN protocol. In Mbed OS, the Thread stack runs in its own RTOS thread using an internal event scheduler. Mbed OS provides the [Mesh C++ API](/docs/v5.8/reference/mesh-api.html) for building Thread applications.
 
 - To connect to the Thread network, use the [Thread interface API](https://github.com/ARMmbed/mbed-os/blob/master/features/nanostack/FEATURE_NANOSTACK/mbed-mesh-api/mbed-mesh-api/ThreadInterface.h).
 - For the socket communication over the Thread network, use the [Mbed sockets API](/docs/v5.8/reference/network-socket.html).
@@ -136,7 +136,7 @@ Now, the Thread network is ready to accept new joiner devices.
 
 The Mbed OS Thread stack supports all three types of commissioners. You can create an external commissioner application by using the Thread MeshCoP protocol or use the Mbed OS APIs (`thread_commissioning_api.h`) to implement a native or an on-mesh commissioner. Currently, there is no reference implementation for native or on-mesh commissioners. External commissioning is supported through the [Nanostack border router](https://github.com/ARMmbed/nanostack-border-router). An external [Commissioning application](https://play.google.com/store/apps/details?id=org.threadgroup.commissioner) (Android) is already available. Also an IOS version will be available soon.
 
-See [Thread commissioning guide](/docs/v5.8/tutorials/mesh.html#thread-commissioning) how to commission a Thread device to the network in practice.
+See [Thread commissioning guide](/docs/v5.8/reference/technology.html#thread-commissioning) how to commission a Thread device to the network in practice.
 
 #### The maturity of the Mbed OS Thread implementation