[MIRROR] Splits projectiles into different files for readability (#5800)

* Splits projectiles into different files for readability

* Update tgstation.dme

* I love how the dme cleans itself up

code/modules/projectiles/projectile/bullets/grenade.dm

@@ -0,0 +1,12 @@
+// 40mm (Grenade Launcher
+
+/obj/item/projectile/bullet/a40mm
+	name ="40mm grenade"
+	desc = "USE A WEEL GUN"
+	icon_state= "bolter"
+	damage = 60
+
+/obj/item/projectile/bullet/a40mm/on_hit(atom/target, blocked = FALSE)
+	..()
+	explosion(target, -1, 0, 2, 1, 0, flame_range = 3)
+	return TRUE