EvalScope integration: one-command evaluation support for BFCL-v3 and BFCL-v4

Hi ShishirPatil/gorilla maintainers,

EvalScope now supports BFCL-v3 and BFCL-v4. This gives users another way to run the benchmark when they want a standardized evaluation workflow around OpenAI-compatible model endpoints, saved predictions, scoring, and report generation.

This may be useful for users who find this repository while setting up BFCL-v3 and BFCL-v4 and want a quick path to evaluate a hosted or locally served model.

Example:

evalscope eval \
  --model YOUR_MODEL \
  --api-url OPENAI_API_COMPAT_URL \
  --api-key EMPTY_TOKEN \
  --datasets bfcl_v4 bfcl_v3 \
  --limit 10

Docs: https://evalscope.readthedocs.io/en/latest/third_party/bfcl_v4.html
Additional guide: https://evalscope.readthedocs.io/en/latest/third_party/bfcl_v3.html
EvalScope repo: https://github.com/modelscope/evalscope

We can also open a small PR adding this as a README/Docs note, linked to this issue.