README: shorten HF Space title to "Carbon"

Trims the Space's frontmatter title from "Carbon DNA Continuation"
(the original prototype name) to just "Carbon", matching how the
brand is used across the demo and the model collection.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -1,5 +1,5 @@
 ---
-title: Carbon DNA Continuation
+title: Carbon
 emoji: 🧬
 colorFrom: gray
 colorTo: indigo