Rename benchmark to guide in readme file

Description

Remove this section if you don't have related PRs.

[x] I've read the guidelines for contributing to this repository.
[x] I've followed the conventions in the PR title.
[x] I've added tests that prove my fix is effective or that my feature works.
[x] I've updated the readme with the relevant information (if needed).
[x] I've added usage information (if the PR introduces new options)
[x] I've included a "before" and "after" example to the description (if the PR is a user interface change).