Updating tracing doc for new spans (#272)

Author: rm-openai

docs/tracing.md

@@ -35,6 +35,9 @@ By default, the SDK traces the following:
 -   Function tool calls are each wrapped in `function_span()`
 -   Guardrails are wrapped in `guardrail_span()`
 -   Handoffs are wrapped in `handoff_span()`
+-   Audio inputs (speech-to-text) are wrapped in a `transcription_span()`
+-   Audio outputs (text-to-speech) are wrapped in a `speech_span()`
+-   Related audio spans may be parented under a `speech_group_span()`
 
 By default, the trace is named "Agent trace". You can set this name if you use `trace`, or you can can configure the name and other properties with the [`RunConfig`][agents.run.RunConfig].
 
@@ -76,7 +79,11 @@ Spans are automatically part of the current trace, and are nested under the near
 
 ## Sensitive data
 
-Some spans track potentially sensitive data. For example, the `generation_span()` stores the inputs/outputs of the LLM generation, and `function_span()` stores the inputs/outputs of function calls. These may contain sensitive data, so you can disable capturing that data via [`RunConfig.trace_include_sensitive_data`][agents.run.RunConfig.trace_include_sensitive_data].
+Certain spans may capture potentially sensitive data.
+
+The `generation_span()` stores the inputs/outputs of the LLM generation, and `function_span()` stores the inputs/outputs of function calls. These may contain sensitive data, so you can disable capturing that data via [`RunConfig.trace_include_sensitive_data`][agents.run.RunConfig.trace_include_sensitive_data].
+
+Similarly, Audio spans include base64-encoded PCM data for input and output audio by default. You can disable capturing this audio data by configuring [`VoicePipelineConfig.trace_include_sensitive_audio_data`][agents.voice.pipeline_config.VoicePipelineConfig.trace_include_sensitive_audio_data].
 
 ## Custom tracing processors