docs: document Node.js 27 introduction plans

[MikeMcC399]

• relates to Prepare for Node.js 27 pre-release (Alpha) / release #2524

Description

Node.js 27 is added to the CONTRIBUTING > Version Updates document section to provide a statement of direction.

The statement documents the intention to publish Docker images based on Node.js 27 Alpha releases.

The exact readiness for releasing node images based on Node.js 27 Alpha releases is left open for the possibility of releasing with the first Alpha release or with a later Alpha release. This will need to be determined after preparation work has been done.

Motivation and Context

The blog post Evolving the Node.js Release Schedule, March 10, 2026, announced the plan to release Node.js 27 Alpha in Oct 2026, followed by Node.js 27.0.0 in April 2027 and included the schedule information for the new model that Node.js 27 is planning to follow. schedule.json now includes concrete milestones:

Milestone	Date
Alpha begin	2026-10-28
Start (27.0.0)	2027-04-22
Enters LTS	2027-10-20
End of Life	2030-04-30

According to the blog post, Alpha versioning follows semver prerelease format (e.g., 27.0.0-alpha.1) and semver-major changes are allowed during this phase.

The repo is not yet set up to deal with the release of Node.js 27 Alpha versions.

Further release details for the future Node.js 27 release line can be expected from the Node.js Releasers Team
as the current descriptions are updated and replaced.

Testing Details

N/A

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.