feat: add OpenAI key to create-llama

packages/create-llama/create-app.ts

packages/create-llama/index.ts

packages/create-llama/templates/index.ts

packages/create-llama/templates/types.ts

...ages/create-llama/templates/types/simple/express/index.ts

.../create-llama/templates/types/simple/express/package.json

packages/create-llama/templates/types/simple/fastapi/main.py

...reate-llama/templates/types/simple/fastapi/pyproject.toml

...s/create-llama/templates/types/streaming/express/index.ts

...eate-llama/templates/types/streaming/express/package.json

...es/create-llama/templates/types/streaming/fastapi/main.py

...te-llama/templates/types/streaming/fastapi/pyproject.toml