feat: Make suggest next questions configurable (#275)

.changeset/cyan-buttons-clean.md

helpers/env-variables.ts

helpers/python.ts

.../components/llamaindex/typescript/streaming/suggestion.ts

templates/components/services/python/file.py

templates/components/services/python/suggestion.py

...pes/multiagent/fastapi/app/api/routers/vercel_response.py

...ypes/streaming/fastapi/app/api/routers/vercel_response.py

templates/types/streaming/fastapi/app/api/services/file.py

...es/types/streaming/fastapi/app/api/services/suggestion.py

templates/types/streaming/fastapi/pyproject.toml