docs(README): fix leftover img alt text to match tracking caption

Update <img> alt from 'Self-attention visualization' to 'Point tracking: Motif vs V-JEPA 2.1' for consistency with the caption.

README.md

@@ -22,7 +22,7 @@ Trained on **~1/3 the data of DINOv3** (0.5B vs 1.7B samples), it still reaches
 performance across image and video benchmarks — and leads on DAVIS video tracking.
 
 <p align="center">
-  <img src="assets/haaland_full_attn_blk20.gif" width="480" alt="Self-attention visualization on a video clip"/>
+  <img src="assets/haaland_full_attn_blk20.gif" width="480" alt="Point tracking on a video clip: Motif vs V-JEPA 2.1"/>
 </p>
 <p align="center"><em>Point tracking on a video clip (top: Motif, bottom: V-JEPA 2.1) — a query point propagated across frames by patch-feature cosine similarity. Motif stays locked on the subject noticeably better than V-JEPA 2.1.</em></p>