docs: adds bifrost to frameworks section

[sammaji]

🚀 Summary

Adds bifrost - ai gateway to frameworks section.

✅ Checklist

• I have read the contribution guidelines
• The tool is AI-related and useful for developers
• I have added a short, clear description of the tool
• The link is not a duplicate of an existing one
• The title of the link is properly capitalized
• The link follows the Awesome List format (- [Tool Name](link) – description)
• My change does not include unrelated files or changes

📌 Why is this tool awesome?

Bifrost is an ai gateway that supports 20+ providers out of the box and custom providers.

• Openai compatible apis for 20+ supported providers
• Anthropic / google / azure native endpoints - https://docs.getbifrost.ai/integrations/anthropic-sdk/overview
• Governance features (virtual keys, budget, rbac) - https://docs.getbifrost.ai/features/governance/virtual-keys
• Built-in observability - https://docs.getbifrost.ai/features/observability/otel
• Compatibility with LiteLLM SDK - https://docs.getbifrost.ai/features/litellm-compat
• MCP Code Mode - https://www.getmaxim.ai/bifrost/blog/bifrost-mcp-gateway-access-control-cost-governance-and-92-lower-token-costs-at-scale

🔗 Link

https://getmaxim.ai/bifrost
https://docs.getbifrost.ai

📝 Additional context

N/A

[sammaji]

Hey @a69 quick review?