Rework benchmarks in README #122
Description
#115 (comment): We could have a pre-collapsed performance sections for people that really care about the numbers. However, we should probably get rid of the numbers in the README altogether. They are very old anyway and at this point likely misleading.
My thoughts: It would be nice to have a graph comparing performance with other BVH implementations, especially other Rust crates. And/or a diagram like I described here.