Adds a machine gun variant of Earendels Ironclad as well as a land-turret of the mortar that acts as a mid-game artillery alternative. Also adds a poison capsule variant of the mortar ammunition.
In the Physical-Projectile-Damage-1-7 bonus technologies, I replaced the type = "turret-attack", turret_id = "mortar-turret" with the type = "ammo-damage", ammo_category = "mortar-bomb".