feat: migrate legacy docs (#1568)

...c/content/docs/llamaindex/getting_started/setup/meta.json

...rc/content/docs/llamaindex/getting_started/setup/next.mdx

...rc/content/docs/llamaindex/getting_started/setup/node.mdx

...tent/docs/llamaindex/getting_started/setup/typescript.mdx

...rc/content/docs/llamaindex/getting_started/setup/vite.mdx

...ocs/llamaindex/getting_started/starter_tutorial/agent.mdx

...s/llamaindex/getting_started/starter_tutorial/chatbot.mdx

.../getting_started/starter_tutorial/images/create_llama.png

...ocs/llamaindex/getting_started/starter_tutorial/meta.json

...arted/starter_tutorial/retrieval_augmented_generation.mdx

...g_started/starter_tutorial/structured_data_extraction.mdx

...next/src/content/docs/llamaindex/guide/agents/1_setup.mdx

...c/content/docs/llamaindex/guide/agents/2_create_agent.mdx

...rc/content/docs/llamaindex/guide/agents/3_local_model.mdx

...rc/content/docs/llamaindex/guide/agents/4_agentic_rag.mdx

.../content/docs/llamaindex/guide/agents/5_rag_and_tools.mdx

...src/content/docs/llamaindex/guide/agents/6_llamaparse.mdx

...ext/src/content/docs/llamaindex/guide/agents/7_qdrant.mdx

...ontent/docs/llamaindex/guide/agents/images/agent_flow.png

apps/next/src/content/docs/llamaindex/guide/agents/meta.json