feat: add /api/chat e2e test (uses openai key) (#287)

.github/workflows/e2e.yml

packages/create-llama/create-app.ts

packages/create-llama/e2e/basic.spec.ts

packages/create-llama/e2e/utils.ts

packages/create-llama/index.ts

packages/create-llama/templates/types.ts