default to havoc, lighter and works on wayland

Index: docs/menu.xml
--- docs/menu.xml.orig
+++ docs/menu.xml
@@ -59,7 +59,7 @@
     <action name="Execute" command="firefox" />
   </item>
   <item label="Terminal">
-    <action name="Execute" command="alacritty" />
+    <action name="Execute" command="havoc" />
   </item>
   <item label="Reconfigure">
     <action name="Reconfigure" />
