add lora demo video

Author: lucylq

program-data-separation/cpp/lora_example/README.md

@@ -237,3 +237,6 @@ I 00:00:50.189743 executorch:text_llm_runner.cpp:206] RSS after finishing text g
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 The ExecuTorch-trained adapter model has domain knowledge of ExecuTorch codebase, whereas the Nobel-prize trained adapter model does not.
+
+## Demo video
+![LoRA with adapters trained on executorch documentation and recent Nobel prize winners](lora_demo_3.mov)