feat(genapi): add audio file conversion instructions to faq

Added instructions for converting m4a audio files to supported formats using ffmpeg and VLC.

Author: fpagny

pages/generative-apis/faq.mdx

@@ -152,6 +152,15 @@ If you require higher maximum output tokens, you can use [Managed Inference](htt
 ### Can I use OpenAI libraries and APIs with Scaleway's Generative APIs?
 Yes, Scaleway's Generative APIs are designed to be compatible with OpenAI libraries and SDKs, including the OpenAI Python client library and LangChain SDKs. This allows for seamless integration with existing workflows.
 
+### How can I convert audio files to a supported format?
+For audio transcription, supported formats are: `flac`, `mp3`, `mpeg`, `mpga`, `oga`, `ogg`, `wav`.
+For unsupported format such as `m4a`, we recommend to use third party librairies or tools to perform the conversion such as [ffmpeg](https://www.ffmpeg.org/) or [VLC](https://www.videolan.org/vlc/).
+For example, you can convert an `m4a` file to `mp3` using `ffmpeg` with:
+```bash
+ffmpeg -i audio-file.m4a audio-file.mp3
+```
+where `audio-file.m4a` is your original file.
+
 ## Usage and management
 
 ### Do model licenses apply when using Generative APIs?