Updated plugin to 1.21.10
No other changes.

Dev Log:
Had to update deprecated PlayerArgument for commands.

in commands_specific_levels, upon reaching level 2 you were rewarded with '1', and level 3 with '2', this is now fixed to match the correct level.

Player data will now also be saved when the server shuts down.

I also added the placeholders to the resources page at the bottom, I'm sorry I forgot to share them

Nothing important, just some efficiency and code improvements