feat: generate llama pack example (#429)

.changeset/ten-sheep-relate.md

packages/create-llama/create-app.ts

packages/create-llama/helpers/constant.ts

packages/create-llama/helpers/index.ts

packages/create-llama/helpers/llama-pack.ts

packages/create-llama/helpers/repo.ts

packages/create-llama/helpers/types.ts

packages/create-llama/index.ts

packages/create-llama/questions.ts

...s/components/sample-projects/llamapack/README-template.md

...lates/components/sample-projects/llamapack/pyproject.toml