Balance change

Made the Dox do less damage, nerfing the camel rider too, making the
melee units durable but not overwhelming

Changed arrows to fire at lower height, making them slightly more
accurate, but still requiring a proper bombardment to kill small fast
units, migh consider a kind of boiling oil tower to deal with single dox
rushes and camels/horses

Changed the ballista's ammo to be slower, preventing it looking like a
insta gib, espesaly on ships

Slowed the ballista and archer so they are eaiser to catch while firing
on the move