Social preview en tete du README

Author: Guillain-RDCDE

README.md

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+<p align="center">
+  <img src="docs/social-preview.jpg" width="100%" alt="FLAC Detective — catch lossy files masquerading as FLAC">
+</p>
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 # 🎵 FLAC Detective
 
 [![PyPI version](https://img.shields.io/pypi/v/flac-detective)](https://pypi.org/project/flac-detective/)