Restore trailing newline (engine issue tracked in QuantEcon/action-translation#116)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: mmcky

lectures/var_dmd.md

@@ -752,4 +752,4 @@ $$ (eq:checkXevoln2)
 
 你可以在这里找到DMD的Python实现：
 
-https://mathlab.sissa.it/pydmd
+https://mathlab.sissa.it/pydmd