overall slightly rebalanced

Just some small changes to the addoninfo and image.

Just corrected a little mistake. No actual changes gameplaywise.

Another little bugfix. Hopefully it will work this time. Last time nothing changed for some reason.

Fixed the amount of specials that can spawn. Accidently set it to 10 for some reason.

Drastically decreased the difficulty. It was almost impossible before. Now it is just hard.

Some infected were made slightly weaker. And there can be only one charger and only one jockey.

-bugfixes