Add byoa telemetry to nav tree

Author: kbatuigas

modules/ROOT/nav.adoc

@@ -60,6 +60,7 @@
 ** xref:ai-agents:observability/index.adoc[Transcripts]
 *** xref:ai-agents:observability/concepts.adoc[Concepts]
 *** xref:ai-agents:observability/view-transcripts.adoc[View Transcripts]
+*** xref:ai-agents:observability/ingest-custom-traces.adoc[Ingest Traces from Custom Agents]
 
 * xref:develop:connect/about.adoc[Redpanda Connect]
 ** xref:develop:connect/connect-quickstart.adoc[Quickstart]