Sync saddle-points docs with problem-specifications (#725)

The saddle-points exercise has been overhauled as part of a project
to make practice exercises more consistent and friendly.

For more context, please see the discussion in the forum, as well as
the pull request that updated the exercise in the problem-specifications
repository:

- https://forum.exercism.org/t/new-project-making-practice-exercises-more-consistent-and-human-across-exercism/3943

Author: kytrinyx

exercises/practice/saddle-points/.docs/instructions.md

@@ -3,7 +3,7 @@
 Your task is to find the potential trees where you could build your tree house.
 
 The data company provides the data as grids that show the heights of the trees.
-The rows of the grid represent the north-south direction, and the columns represent the east-west direction.
+The rows of the grid represent the east-west direction, and the columns represent the north-south direction.
 
 An acceptable tree will be the the largest in its row, while being the smallest in its column.