Kimetsunoyaiba Tweaks

• Added base swords for love, serpent, sound, insect, and stone
• Added generic demon slayer entity
  • /spawndemonslayer <breathing style> <slayer level (0-4)> [optional gender] [optional skin number]
  • You can go through the tab suggestions to see the availaable options for each one, and the default options (if left blank) are just random
  • demon slayers of level 0 will spawn with no armor, and a training sword, so they can only use one breathing form
  • demon slayers of level 4 will be senior, and they will use the senior animations
• Added Muichiro Full Potential entity
• Added some armor items (Muichiro FP hair and haori, andon bakama uniform pants)

Note: while there is a beast sword item, it doesn't work yet, I haven't implemented it