Slime Origin

Adds new downsides, fixes bugs, there's a pretty picture in the mod menu now what's not to love?

Changelog from Beta:

• Fixed an issue where players were dying instead of shrinking #1
• Fixed some truly wild code on my part that was preventing more than one shrink

Full Changelog:

• Added mod menu icon
• Due to popular demand, increased jump height from 1.5 blocks to 2
• Added "Melting" downside, causes fire damage when in biomes with a [temperature](https://minecraft.gamepedia.com/Biome#Temperature) value above one.
• Also added a "slimeorigin:temperature" condition for any data pack developers. Compares a chosen value to a float of the temperature at the players current location.
• Added a downside to "Improved Jump", player movement speed is decreased by 25%.
  • Known Issue: FOV is affected by the movement speed attribute, so is greatly reduced when using the origin, a current fix is to turn down FOV Effects in accessibility settings.