feat: begin adding integration docs

...es/integrations/pydantic-ai/chatbot-with-guardrails.ipynb

docs/integrations/aurelio.md

docs/integrations/cohere.md

docs/integrations/integrations.md

docs/integrations/jina.md

docs/integrations/litellm.md

docs/integrations/mistral.md

docs/integrations/nvidia.md

docs/integrations/openai.md

docs/integrations/pydantic-ai.md

docs/integrations/voyage.md