Uses the glob, image, and rayon crates to resize all of the .jpg in the current directory
into a thumbnails folder.
run with: cargo run --release with some .jpg images in the top level directory of the repository.
Test was run against 196 images from an 18MP dslr (~1GB of images).
Used the Nearest resize algorithm from the image crate, resizing to a 300px thumbnail.
Results from i5 4670k (4 cores/threads):
- No rayon: 63.837 seconds ~50% cpu usage
- With rayon: 33.094 seconds ~97% cpu usage