sequtils.CountIt not recognised - Possible AoC2021 spoiler

[freeflow]

@SolitudeSF Thanks for the feedback. I'm using nim version 1.6. I'm doing 
advent of code in nim as a challenge from amateur coding (i don't get paid...) 
in VBA. So there are lots of concepts in nim I need to get my head around. Look 
like tonighht's reading is about when and where to use new.