Add ai-evaluation and traceAI to Evals section

[SuhaniNagpal7]

Summary

• Adds ai-evaluation — LLM evaluation framework with 50+ metrics, LLM-as-Judge, and guardrail scanners
• Adds traceAI — OpenTelemetry-native tracing framework for LLM/agent apps

Both added under the AI Engineering → Evals section.

[SuhaniNagpal7]

Hi @owainlewis, following up on this PR. Let me know if any changes are needed on my end to get it merged. Thanks!