chore: update README

Author: shigma

packages/core/README.md

@@ -1 +1,7 @@
-# cordis
+<div align="center">
+  <h1 id="satori">Cordis</h1>
+</div>
+
+A Meta-Framework of Spatiotemporal Composability.
+
+**Cordis is under active development. The API is not yet stable and may change without notice. Documentation and paper is coming soon.**