Update benchmark documentation with image

Author: Tortar

docs/src/benchmark.md

@@ -21,7 +21,7 @@ We also tried to evaluate the performance of the procedures on persistent data.
 performance of weighted sampling with replacement from 100 GB of data in the arrow format stored on
 disk:
 
-[comparison_ondisk_algs.pdf](https://github.com/user-attachments/files/22069870/comparison_ondisk_algs.pdf)
+![comparison_ondisk_algs](https://github.com/user-attachments/assets/622c5d03-07f2-428c-9bb5-6d6fcc629bec)
 
 the "chunks" method uses `StatsBase.sample` along with the merging methods of this package to sample
 subsequent chunks of the stored data and then recombine the samples. The other methods employ the