LoRA Training Script for Image Editing with FLUX Kontext

**Is your feature request related to a problem? Please describe.**
Currently, the provided fine-tuning script for FLUX Kontext (train_dreambooth_lora_flux_kontext.py) focuses exclusively on T2I. This is no example to follow to fine-tune the model for instruction-based image editing tasks.

**Describe the solution you'd like.**
I would like an official example script for LoRA fine-tuning of FLUX Kontext specifically for image editing.

**Additional context.**
I'd like to express my appreciation for the T2I fine-tuning script—it's a fantastic resource!
Given FLUX Kontext's powerful capabilities, enabling straightforward fine-tuning for image editing would unlock many new applications for the community.

The current T2I script for reference:
examples/dreambooth/train_dreambooth_lora_flux_kontext.py