[docs]: improve structure for kt-kernel (#1624)

* [docs]: improve structure for kt-kernel

* Update doc/en/kt-kernel/README.md

doc/SUMMARY.md

@@ -8,17 +8,15 @@
 # Tutorial 
 - [SFT part](en/SFT/README.md)
   - [SFT developer tech notes](en/SFT/KTransformers-Fine-Tuning_Developer-Technical-Notes.md)
-  - [Injection Tutorial](en/injection_tutorial.md)
+  - [Injection Tutorial](en/SFT/injection_tutorial.md)
   <!-- - [Multi-GPU Tutorial](en/multi-gpu-tutorial.md) -->
   <!-- - [Use FP8 GPU Kernel](en/fp8_kernel.md) -->
   <!-- - [Use AMD GPU](en/ROCm.md) -->
 <!-- - [Deepseek-R1/V3 Show Case/Tutorial](en/DeepseekR1_V3_tutorial.md) -->
 <!-- - [Why KTransformers So Fast](en/deepseek-v2-injection.md) -->
-
-## KT-kernel part
 <!-- # For Developer
 - [Makefile Usage](en/makefile_usage.md) -->
-
+- [kt-kernel part](en/kt-kernel/README.md)
 # FAQ
 - [FAQ](en/FAQ.md)
 <!-- # V3 Reproduction

doc/en/SFT/README.md

@@ -1 +1 @@
-#SFT Docs
+# SFT Docs

doc/en/kt-kernel/README.md

@@ -0,0 +1,2 @@
+# kt-kernel Docs
+To be written...