CRI documentation improvements

[nekwar]

Description

• Add clarification on dynamic containerd configuration
• Update nvidia-container-runtime section with up-to-date instructions

Fixes # (issue)
#4558

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist:

• My code follows the style guidelines of this project
• My commit messages are signed-off
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[dvirassamy]

I had a similar confusion.

You start reading about changing containerd.toml and removing the magic flag.

However the next paragraph provides the better solution, as from 1.27, where you can use the reconciler. which is a better solution as containerd.toml is still managed by k0s but you can extend it or customize it with side configs.

If there is not a good reason to modify containerd.toml, I would suggest to push to the top of the documentation the recommendation solution which uses the reconciler.