Revert "Flatten services/ nesting: promote speech and function-calling to top level"

This reverts commit e1939ecd44.

examples/README.md

@@ -63,11 +63,10 @@ Progressive introduction to Pipecat, from minimal TTS to a full voice agent with
 
 ### [`services/`](./services/)
 
-Full STT + LLM + TTS pipelines showcasing different speech service providers (Deepgram, ElevenLabs, Cartesia, etc.)
+Service provider integration examples, organized into subfolders:
 
-### [`function-calling/`](./function-calling/)
-
-Function calling with different LLM providers (OpenAI, Anthropic, Google, etc.)
+- **[`speech/`](./services/speech/)** — Full STT + LLM + TTS pipelines showcasing different speech service providers (Deepgram, ElevenLabs, Cartesia, etc.)
+- **[`function-calling/`](./services/function-calling/)** — Function calling with different LLM providers (OpenAI, Anthropic, Google, etc.)
 
 ### [`transcription/`](./transcription/)