README.md of integration test is not up-to-date

[Gekko0114]

Hi,
I am creating the environment running integration test.
However, this document is not up-to-date.
https://github.com/containers/youki/blob/main/tests/contest/contest/README.md
For example, crates/youki_integration-test directory doesn't exist.

Could you update the README of integration-test?

[utam0k]

@Gekko0114 Thanks for your report. I have fixed it.
#2680

If you want me to update other docs, please tell me. Of course, we are welcome to update the docs on your own.

[Gekko0114]

Thank you so much!