Update doc/dev/2025-12-19-echokit-day-20-local-gpt-sovits.md

Co-authored-by: Copilot <[email protected]>

Author: alabulei1

doc/dev/2025-12-19-echokit-day-20-local-gpt-sovits.md

@@ -1,5 +1,5 @@
 ---
-slug: echokit-30-days-day-19-fish-audio-tts
+slug: echokit-30-days-day-20-local-gpt-sovits
 title: "Day 20: Running GPT-SoVITS Locally as EchoKit’s TTS Provider | The First 30 Days with EchoKit"
 tags: [echokit30days, tts]
 ---