Update ZeRO-Offload blog post link (#401)

Co-authored-by: Shaden Smith <Shaden.Smith@microsoft.com>
Co-authored-by: Jeff Rasley <jerasley@microsoft.com>

docs/_tutorials/zero-offload.md

@@ -6,7 +6,7 @@ We recommend that you read the tutorials on [Getting Started](/getting-started/)
 ZeRO-Offload is a ZeRO optimization that offloads the optimizer memory and computation from the GPU to the host CPU. ZeRO-Offload enables large models with up to 13 billion parameters to be efficiently trained on a single GPU. In this tutorial we will use ZeRO-Offload to train a 10-billion parameter GPT-2 model in DeepSpeed. Furthermore, *using ZeRO-Offload in a DeepSpeed model is quick and easy because all you need is to change a few configurations in the DeepSpeed configuration json*. No code changes are needed.
 
 ## ZeRO-Offload Overview
-For large model training, optimizers such as [Adam](https://arxiv.org/abs/1412.6980), can consume a significant amount of GPU compute and memory. ZeRO-Offload reduces the GPU compute and memory requirements of such models by leveraging compute and memory resources on the host CPU  to execute the optimizer. Furthermore, to prevent the optimizer from becoming a bottleneck, ZeRO-Offload uses DeepSpeed's highly optimized CPU implementation of Adam called [DeeSpeedCPUAdam](https://github.com/microsoft/DeepSpeed/tree/master/deepspeed/ops/adam). DeepSpeedCPUAdam is 5X--7X faster than the standard PyTorch implementation. To deep dive into the design and performance of ZeRO-Offload, please see our blog post [[XXXX]()].
+For large model training, optimizers such as [Adam](https://arxiv.org/abs/1412.6980), can consume a significant amount of GPU compute and memory. ZeRO-Offload reduces the GPU compute and memory requirements of such models by leveraging compute and memory resources on the host CPU  to execute the optimizer. Furthermore, to prevent the optimizer from becoming a bottleneck, ZeRO-Offload uses DeepSpeed's highly optimized CPU implementation of Adam called [DeeSpeedCPUAdam](https://github.com/microsoft/DeepSpeed/tree/master/deepspeed/ops/adam). DeepSpeedCPUAdam is 5X--7X faster than the standard PyTorch implementation. To deep dive into the design and performance of ZeRO-Offload, please see our [blog post](https://www.microsoft.com/en-us/research/blog/deepspeed-extreme-scale-model-training-for-everyone/#toc-heading-3).
 
 ## Training Environment
 For this tutorial, we will configure a 10 billion parameter GPT-2 model using the DeepSpeed [Megatron-LM](https://github.com/microsoft/DeepSpeedExamples/tree/master/Megatron-LM) GPT-2 code. We advise stepping through the Megatron-LM [tutorial](/megatron/) if you have not previously done so. We will use a single [NVIDIA Tesla V100-SXM3 Tensor Core GPU](https://www.nvidia.com/en-us/data-center/v100/) with 32GB RAM for this exercise.