add run app option (#399)

.changeset/nervous-numbers-swim.md

packages/create-llama/create-app.ts

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

packages/create-llama/e2e/utils.ts

packages/create-llama/helpers/python.ts

packages/create-llama/helpers/run-app.ts

packages/create-llama/helpers/types.ts

packages/create-llama/helpers/typescript.ts

packages/create-llama/index.ts

packages/create-llama/questions.ts

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

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

...reate-llama/templates/types/streaming/nextjs/package.json