Fix readme link to tts

Author: zipus

README.md

@@ -42,7 +42,7 @@ docker run -d -e OPENAI_API_KEY=<YOUR_API_KEY> -e TTS_PROVIDER=EDGETTS -e EDGETT
 The AI model defaults to `gpt-3.5-turbo` but you can adjust this by setting the `AI_COMPLETION_MODEL` environment variable (e.g. to `gpt-4` if your `OPENAI_API_KEY` has access to it)
 
 You can configure the language by setting the `LANGUAGE` environment variable to the corresponding ISO-639-1 code. The default is `en`.
-Languages other than English are currently only supported when using the `gTTS` or `edge_tts` providers for text-to-speech. The TTS provider can be selected by setting the environment variable `TTS_PROVIDER` to one of the values in [tts.py](./app/tts.py).
+Languages other than English are currently only supported when using the `gTTS` or `edge_tts` providers for text-to-speech. The TTS provider can be selected by setting the environment variable `TTS_PROVIDER` to one of the values in [tts.py](./backend/tts.py).
 
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