fix(doc): reference count_paths from top-level documentation

[samueltardieu]

No description provided.

[codspeed-hq]

CodSpeed Performance Report

Merging #622 will degrade performances by 24.88%

_{Comparing push-pznrzowpoyzx (eae1dd2) with main (045eaf3)}

Summary

⚡ 2 improvements
❌ 5 regressions
✅ 29 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	push-pznrzowpoyzx	Change
❌	fill-corner_to_corner_bfs	1.3 ms	1.5 ms	-16.19%
⚡	fill-corner_to_corner_dfs	4 ms	3.5 ms	+12.77%
❌	fill-corner_to_corner_dijkstra	1.2 ms	1.5 ms	-19.95%
❌	fill-no_path_astar	1.2 ms	1.5 ms	-24.88%
❌	fill-no_path_bfs	1.1 ms	1.4 ms	-20.03%
❌	fill-no_path_dijkstra	1.2 ms	1.5 ms	-16.67%
⚡	no_path_fringe	2.1 ms	1.9 ms	+11.72%