add minimal verifiers example (#472)

examples/verifiers/README.md

@@ -0,0 +1,38 @@
+## Setup
+
+Prepare virtual environment, e.g.
+
+```bash
+python -m venv venv
+source venv/bin/activate
+```
+
+Install dependencies
+
+```bash
+pip install -r requirements.txt
+pip install flash-attn --no-build-isolation
+```
+
+Login to W&B and HuggingFace if desired
+
+```bash
+wandb login
+huggingface-cli login
+```
+
+## Training
+
+Here we assume two GPUs, with one used for inference (vLLM) and the other for training (accelerate). You may need to adjust some settings for different GPU configs.
+
+Run the vLLM server for inference:
+
+```bash
+CUDA_VISIBLE_DEVICES=0 vf-vllm --model Qwen/Qwen2.5-1.5B-Instruct --tensor-parallel-size 1
+```
+
+Run the training script using accelerate:
+
+```bash
+CUDA_VISIBLE_DEVICES=1 accelerate launch --config-file zero3.yaml --num-processes 1 vf_rg.py
+```