docs: fix speaker tag naming (#63)

Author: Kilerd

api-reference/openapi.json

@@ -2137,7 +2137,7 @@
         "type": "object"
       },
       "TTSRequest": {
-        "description": "Request body for text-to-speech synthesis. Supports both single-speaker and multi-speaker synthesis.\n\n## Single Speaker\nProvide either `reference_id` (string) pointing to a voice model, or `references` (array of ReferenceAudio) for zero-shot cloning.\n\n## Multiple Speakers (Dialogue)\nFor multi-speaker synthesis, provide:\n- `reference_id`: array of voice model IDs, e.g., [\"speaker-a-id\", \"speaker-b-id\"]\n- `text`: use speaker tags [0], [1], etc. to indicate speaker changes, e.g., \"[0]Hello![1]Hi there!\"\n\nAlternatively, for zero-shot multi-speaker:\n- `references`: 2D array where each inner array contains references for one speaker\n- `reference_id`: array of identifiers (can be arbitrary strings for zero-shot)\n\n## Example (Multi-Speaker with Model IDs)\n```json\n{\n  \"text\": \"[0]Good morning![1]Good morning! How are you?[0]I'm great, thanks!\",\n  \"reference_id\": [\"model-id-alice\", \"model-id-bob\"]\n}\n```",
+        "description": "Request body for text-to-speech synthesis. Supports both single-speaker and multi-speaker synthesis.\n\n## Single Speaker\nProvide either `reference_id` (string) pointing to a voice model, or `references` (array of ReferenceAudio) for zero-shot cloning.\n\n## Multiple Speakers (Dialogue)\nFor multi-speaker synthesis, provide:\n- `reference_id`: array of voice model IDs, e.g., [\"speaker-0-id\", \"speaker-1-id\"]\n- `text`: use speaker tags `<|speaker:0|>`, `<|speaker:1|>`, etc. to indicate speaker changes, e.g., \"<|speaker:0|>Hello!<|speaker:1|>Hi there!\"\n\nAlternatively, for zero-shot multi-speaker:\n- `references`: 2D array where each inner array contains references for one speaker\n- `reference_id`: array of identifiers (can be arbitrary strings for zero-shot)\n\n## Example (Multi-Speaker with Model IDs)\n```json\n{\n  \"text\": \"<|speaker:0|>Good morning!<|speaker:1|>Good morning! How are you?<|speaker:0|>I'm great, thanks!\",\n  \"reference_id\": [\"model-id-alice\", \"model-id-bob\"]\n}\n```",
         "type": "object",
         "required": ["text"],
         "properties": {