docs: add README hero demo gif

Looping montage that grows the tslime logo across the four launch presets
(Organic, Constellation, Vinescii, Trademark). Optimized GIF at assets/demos/hero.gif.

Author: tamirelazar

CHANGELOG.md

@@ -15,6 +15,8 @@ First public release.
 - Screensaver and interactive modes; pause, restart, preset/palette cycling at runtime
 - GIF, PNG, and WebM export
 - Window-frame display modes
+- README hero demo: a looping montage that grows the tslime logo across the
+  Organic, Constellation, Vinescii, and Trademark launch presets
 - `vinescii` preset — the vines (flocking) pattern in pure ASCII
 - Experimental: multi-species, choir audio, and GUI (feature-gated); WASM build (standalone crate)
 

README.md

@@ -7,7 +7,9 @@ binary, runs on Linux, macOS, Windows, and over SSH, and works as both a screens
 and an instrument: every simulation parameter can be steered live from the keyboard
 while it runs.
 
-<!-- ws6: hero gif -->
+<p align="center">
+  <img src="assets/demos/hero.gif" alt="tslime growing the logo across the Organic, Constellation, Vinescii, and Trademark presets" width="100%">
+</p>
 
 ## Install