LevelHearts

This version is compatible with previous versions of LevelHearts.

* Updated to Minecraft Forge 31.2.0 for Minecraft 1.15.2
* Added a "One-Hit Knockout" feature; one hit, and you're out.
* Added "LevelHearts Hidden HUD", to hide the health bar (works well with OHKO)
* Added "Always Lose Inventory on Death", the opposite of "Always Lose XP on Death"
* Added a /levelhearts command with the following commands:

  - /levelhearts hearts add <targets> <amount> [heal:(true)|false]
  - /levelhearts hearts set <targets> <amount> [heal:(true)|false]
  - /levelhearts containers add <targets> <amount> [heal:(true)|false]
  - /levelhearts containers set <targets> <amount> [heal:(true)|false]
* Fixed an issue where punishments would not say the correct amount of hearts lost
* Fixed an issue where, if your health was set to below 4 hearts and you had minimal hud enabled, the hearts would bounce forever.