Added a new option for rainbow color glow. (it currently applies to all entity) (unless... there is somekind of easter egg that has snugged itself into this? Right sheep?)
Added the possibility of setting a custom glow color entitytype-specific (check the javadocs, i will updated the wiki in a bit)
Added support of 1.17.1 version and gamerule "overrideTeamColors" to override the color gaven by the minecraft team and use the library's one instead.