Adding solution by rmarbeck (#752)

docs/2024/puzzles/day18.md

@@ -8,6 +8,7 @@ https://adventofcode.com/2024/day/18
 
 ## Solutions from the community
 - [Solution](https://github.com/nikiforo/aoc24/blob/main/src/main/scala/io/github/nikiforo/aoc24/D18T2.scala) by [Artem Nikiforov](https://github.com/nikiforo)
+- [Solution](https://github.com/rmarbeck/advent2024/blob/main/day18/src/main/scala/Solution.scala) by [Raphaël Marbeck](https://github.com/rmarbeck)  
 
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