fixed up package structure

apps/simple/index.ts

apps/simple/package.json

packages/core/package.json

packages/core/src/BaseIndex.ts

packages/core/src/Document.ts

packages/core/src/Embedding.ts

packages/core/src/LLMPredictor.ts

packages/core/src/Node.ts

packages/core/src/Prompt.ts

packages/core/src/QueryEngine.ts

packages/core/src/Reader.ts

packages/core/src/Response.ts

packages/core/src/ResponseSynthesizer.ts

packages/core/src/Retriever.ts

packages/core/src/ServiceContext.ts

packages/core/src/StorageContext.ts

packages/core/src/index.ts

packages/core/src/openai.ts

packages/core/tsconfig.json

pnpm-lock.yaml