Treasures of the dead

Changes:

• Now you can config HEALTH and DAMAGE of every skeleton in treasures_of_the_dead.toml config file;
• Shadow skeleton health 26 -> 22, damage 3 -> 4.5;
• Captain shadow skeleton health 70 -> 60, damage 4 -> 5.5;
• Every treasure now can be placed IN composters and cauldrons (awesome);
• Sea fortress core: removed nbt CooldownTicks, added nbt LastTimeActive, NextTimeActive.
• Now cooldown of the sea fortress core "ticking" while it is not loaded. Meaning  you can clear the fortress, go far away for thousands blocks, return after 30 minutes and the sea fortress will be active again while you wasn't near.