[QoL] Extra HP to Zombies [OPEN]

[grandchild]

As I noticed, a single player can walk among a horde as he can just pass through them with Katana and kill them all, avoiding all meanings of life and self awareness. (Not valuating life)
- Give zombies more HP.
- Nerf Katana
- Strong, but medium speed zombies. (You either run if you been followed by one or approach if you are prepared to kill)

[Awide]

Zombies now spawn with 60 + (0 to 60 )* 3 HP. It is not intended to make them any harder. Player zombies may pose higher threat.