* Add precompute_ref_log_probs to config schema * chore: add description for config * Add test for precompute_ref_log_probs and move to training args * useing precompute logprobs as the default slows down CI as it has to precompute --------- Co-authored-by: NanoCode012 <nano@axolotl.ai> Co-authored-by: Wing Lian <wing@axolotl.ai>