[WIP] feat: remove legacy docs (#1571)

apps/docs/.changeset/tall-parents-add.md

apps/docs/.gitignore

apps/docs/CHANGELOG.md

apps/docs/README-docusaurus.md

apps/docs/babel.config.js

apps/docs/blog/2024-04-26-v0.3.0.md

apps/docs/blog/img/function_tool_example.png

apps/docs/docs/.gitignore

apps/docs/docs/_static/concepts/indexing.jpg

apps/docs/docs/_static/concepts/querying.jpg

apps/docs/docs/_static/concepts/rag.jpg

apps/docs/docs/examples/_category_.yml

apps/docs/docs/examples/agent.mdx

apps/docs/docs/examples/agent_gemini.mdx

apps/docs/docs/examples/chat_engine.mdx

apps/docs/docs/examples/context_aware_agent.mdx

apps/docs/docs/examples/local_llm.mdx

apps/docs/docs/examples/more_examples.mdx

apps/docs/docs/examples/other_llms.mdx

apps/docs/docs/examples/save_load_index.mdx