Fix reference equation

Author: Daniel Precioso, PhD

modules/collective-motion/couzin.qmd

@@ -45,7 +45,7 @@ and towards the poisitions of individuals within the zone of attraction
 
 $$
 \mathbf{d}_a(t+\tau) = \sum^{n_a}_{j \neq i} \frac{\mathbf{v}_j(t)}{|\mathbf{v}_j(t)|}
-$$ {@eq-attraction}
+$$ {#eq-attraction}
 
 If neighbours are found in both orientation and attraction zones, then