docs: add French README_fr.md with EN/FR cross-links and author line

Mirror README.md in French as README_fr.md, link each to the other at
the top, and credit Olivier Cornelis (psychiatrist and dev / data
scientist) in both.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: thiswillbeyourgithub

README.md

@@ -4,10 +4,14 @@
 
 # Parakeet Web
 
+**[English](./README.md) | [Français](./README_fr.md)**
+
 > ⚠️ **EXPERIMENTAL WIP** – Made with care but with AI. Expect bugs, breaking changes, and rough edges.
 
 **Try it now: [parakeetweb.olicorne.org](https://parakeetweb.olicorne.org/)** — no installation required.
 
+Made by Olivier Cornelis, psychiatrist and dev / data scientist ([bio](https://olicorne.org)).
+
 ---
 
 ## Table of Contents