docs: Move nschonni from Collaborators to Maintainers

[nschonni]

Description

Move from the Collaborators list to the Maintainers list.

Motivation and Context

I think prior to the WG discussion it was Simen and I that were the last ones to have the GitHub Maintain access on the team. I've since added the others now in the list to have the same permission.

Testing Details

Example Output(if appropriate)

Types of changes

• Documentation
• Version change (Update, remove or add more Node.js versions)
• Variant change (Update, remove or add more variants, or versions of variants)
• 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 change)
• Other (none of the above)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• All new and existing tests passed.

[MikeMcC399]

It makes sense to align the README role with the one set in the https://github.com/orgs/nodejs/teams/docker team: