Fixes an error in the config when leveling up. The error wasn't anything gamebreaking, it was just trying to send a message that didn't exist.

- Added new feature: EXP Gain Multipliers! By setting this in the config/level system configuration, you can adjust whether people should gain extra exp. This is useful for a server-wide exp boost event, where players gain extra exp for a short time.

- There are also per-player gain multipliers, so you can have specific individual players gain exp at a higher or lower rate. Both of these multipliers can be set with commands in-game or by messing with the right config files.

- As a result of this new change, the config has been adjusted. The config should automatically update, but you will have to go and manually remove the exp-multiplier field in your config.yml and levelsystems.yml files as this field has been replaced by the exp-required-multiplier field.

- The plugin is also fully and officially tested to work on 1.20!

The goal of this update was specifically to add support to have multiple leveling systems running simultaneously. This will allow you to have something like a combat exp leveling system separate from a chat level which is also separate from a combat level. This makes it more versatile for whatever other needs you may have. I've also added a built-in reload command that will reload the config files. Be careful, though, as I don't know what issues may arise from it.

• Added extra leveling systems! By turning this on in your config, you can have multiple leveling systems running at the same time, rather than just one set up by default. If you don't want to use this feature you don't have to touch anything, but if you do, it would be helpful to re-generate your config.yml and milstones.yml. A new "levelsystems.yml" will generate automatically.
  
  
• Started keeping track of config versions to make config updates easier.
  
  
• Added a reload command! Use /sl reload to reload the plugin! Note that this is only recommended to be used when nobody else is online or is actively doing things to receive experience, reloading may cause unforeseen issues and can potentially erase playerdata.

Just a small QOL update. With this update, it is perfectly save to update from 1.0.2, all data will be converted into the new format. This feature will be dropped once I see that no more servers are running version 1.0.2 on the bstats page, which can be found here.

• Added a data converter that converts old data.yml plugin data to the new data format.
• Added the ability to customize the amount of exp individual mobs get in the mobs.yml config file. If a mob is not in the file, the default (as defined in the config.yml) is used
• Fixed a bug which caused an error when trying to use /sl set level without specifying true or false.

This update is a critical update for everyone using the plugin. If at all possible, please please switch to this update from the old version. Numerous bugs have been fixed and data storage has been overhauled entirely to prevent the data from being erased. However, You will lose your data (not config/milestones) upon updating.

New Features:
- Expanded the functionality of the API. Tutorial and documentation coming soon.
- Changed the way the plugin handles data. All data is now handled in - individual files rather than one large data file.
- Re-formatted commands to read /sl set [exp/level] instead of /sl addexp
- Changed /sl addexp to /sl set exp and gave it the ability to remove exp through negative numbers
- Added /sl set level command which allows you to set a player's level.
- Added an update checker which warns you in the console if your version is out of date

Bugfixes:

- Fixed a bug causing players to level too fast
- Fixed a bug causing all plugin data to be erased
- Fixed a bug causing the level up message to always display level 1 or 0

This update likely introduced a number of other bugs I haven't caught yet while simultaneously fixing numerous bugs I haven't yet caught. To report these bugs, please join the discord or make an issue report on the github.

There were some bugs left in the original release version that I overlooked. Should be all fixed with this update.

- Plugin now properly works on all servers whereas before the plugin wouldn't work properly on servers where there was already a playerbase.

- Added a maximum level to the config. Disable the level cap by setting it to 0. The plugin will not break if this is not in the config (level cap will just be disabled), but max-level must be added to the config if you want to use it (defaults to 100)

- Mobkill event will no longer trigger on players.

- Fixed a bug where the default required exp was not being set properly, causing strange leveling behavior and causing new players to level up quicker than they should.

Fixed an incompatibility with most chat plugins that would cause the level prefix not to show up