Add Speechmatics TTS docs

docs.json

@@ -193,6 +193,7 @@
                   "server/services/tts/playht",
                   "server/services/tts/rime",
                   "server/services/tts/sarvam",
+                  "server/services/tts/speechmatics",
                   "server/services/tts/xtts"
                 ]
               },

server/services/supported-services.mdx

@@ -103,6 +103,7 @@ Text-to-Speech services receive text input and output audio streams or chunks.
 | [PlayHT](/server/services/tts/playht)         | `pip install "pipecat-ai[playht]"`     |
 | [Rime](/server/services/tts/rime)             | `pip install "pipecat-ai[rime]"`       |
 | [Sarvam](/server/services/tts/sarvam)         | No dependencies required               |
+| [Speechmatics](/server/services/tts/speechmatics) | `pip install "pipecat-ai[speechmatics]"` |
 | [XTTS](/server/services/tts/xtts)             | `pip install "pipecat-ai[xtts]"`       |
 
 ## Speech-to-Speech

server/services/tts/speechmatics.mdx

@@ -0,0 +1,62 @@
+---
+title: "Speechmatics"
+description: "Text-to-speech service using Speechmatics TTS API"
+---
+
+## Overview
+
+`SpeechmaticsTTSService` provides high-quality low-latency text-to-speech synthesis using Speechmatics TTS API with support for multiple voices and streaming capabilities. The service is optimized for voice AI applications with efficient audio streaming.
+
+<CardGroup cols={2}>
+  <Card
+    title="Speechmatics TTS API Reference"
+    icon="code"
+    href="https://reference-server.pipecat.ai/en/latest/api/pipecat.services.speechmatics.tts.html"
+  >
+    Pipecat's API methods for Speechmatics TTS integration
+  </Card>
+  <Card
+    title="Example Implementation"
+    icon="play"
+    href="https://github.com/pipecat-ai/pipecat/blob/main/examples/foundational/07a-interruptible-speechmatics.py"
+  >
+    Complete example with Speechmatics TTS
+  </Card>
+  <Card
+    title="Speechmatics Documentation"
+    icon="book"
+    href="https://docs.speechmatics.com/text-to-speech/quickstart"
+  >
+    Official Speechmatics TTS API documentation
+  </Card>
+  <Card
+    title="Speechmatics Portal"
+    icon="microphone"
+    href="https://portal.speechmatics.com"
+  >
+    Browse and test available voices
+  </Card>
+</CardGroup>
+
+## Installation
+
+To use Speechmatics services, install the required dependencies:
+
+```bash
+pip install "pipecat-ai[speechmatics]"
+```
+
+## Prerequisites
+
+### Speechmatics Account Setup
+
+Before using Speechmatics TTS services, you need:
+
+1. **Speechmatics Account**: Sign up at [Speechmatics Portal](https://portal.speechmatics.com)
+2. **API Key**: Generate an API key from your dashboard
+3. **Voice Selection**: Choose from available voices
+
+### Required Environment Variables
+
+- `SPEECHMATICS_API_KEY`: Your Speechmatics API key for authentication
+