Add solution link for day 12 (#722)

docs/2024/puzzles/day12.md

@@ -376,6 +376,7 @@ def part2(input: String): Int = {
 - [Solution](https://github.com/aamiguet/advent-2024/blob/main/src/main/scala/ch/aamiguet/advent2024/Day12.scala) by [Antoine Amiguet](https://github.com/aamiguet)
 - [Solution](https://github.com/makingthematrix/AdventOfCode2024/blob/main/src/main/scala/io/github/makingthematrix/AdventofCode2024/DayTwelve.scala) by [Maciej Gorywoda](https://github.com/makingthematrix)
 - [Solution](https://github.com/spamegg1/aoc/blob/master/2024/12/12.worksheet.sc#L191) by [Spamegg](https://github.com/spamegg1/)
+- [Solution](https://github.com/jnclt/adventofcode2024/blob/main/day12/garden-groups.sc) by [jnclt](https://github.com/jnclt)
 
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