Hello, my team and I are having a bit of trouble understanding the metadata portion of Documents within this guide here: https://gpt-index.readthedocs.io/en/latest/how_to/customization/custom_documents.html#metadata

The guide states that By default, the metadata is injected into the text for both embedding and LLM model calls. Does this mean the metadata is also embedded by LlamaIndex along with the original chunk of text? Or is it that the chunk of text is embedded and the metadata is injected in a different data structure?