docs: update README with development warning

EverythingSuckz · EverythingSuckz · commit 457a7668bf82 · 2026-03-23T22:33:58.000-04:00
diff --git a/README.md b/README.md
@@ -1,3 +1,6 @@
+> [!WARNING]
+> This project is under development and is not yet ready for use. Expect frequent breaking changes until the `1.0.0` release.
+
 <p align="center">
   <img src="assets/icon.png" alt="Mirroid" width="128" />
 </p>
