docs: club PyTorch and TensorFlow into a single training card

Merges the separate framework cards into one "Train Models" card
covering PyTorch and TensorFlow, with links to both framework guides.

Author: Bhanu Teja Goshikonda

docs/index.md

@@ -72,17 +72,9 @@ LLM serving is just one example. DLCs cover a range of AI/ML workloads — explo
 
     ---
 
-    Run distributed training with PyTorch on GPU or CPU, with EFA, NCCL, flash-attn, and DeepSpeed pre-installed.
+    Run distributed training with PyTorch or TensorFlow on GPU or CPU, with EFA and NCCL pre-installed for multi-node workloads.
 
-    [PyTorch Guide](pytorch/index.md)
-
--   **Train Models with TensorFlow**
-
-    ---
-
-    Run TensorFlow training on Amazon SageMaker AI with EFA-capable multi-node support on Amazon Linux 2023.
-
-    [TensorFlow Guide](tensorflow/index.md)
+    [PyTorch Guide](pytorch/index.md) · [TensorFlow Guide](tensorflow/index.md)
 
 -   **Build Your Own Image**