docs: add objective contributor ladder criteria

[yada]

Summary

• add measurable eligibility criteria for Maintainers and Code Owners
• require promotion nominations to link public supporting evidence
• recognize equivalent asynchronous community participation
• add a governance review date and annual review cadence
• distinguish administrative no-change reviews from substantive governance amendments

Context

This addresses the remaining contributor-ladder and document-currency recommendations from the CNCF Microcks governance review:

cncf/toc#2099

Because this changes governance policy, the PR will require a formal organization-balanced Maintainer vote.

[yada]

@microcks/maintainers :
This PR introduces objective promotion criteria for Maintainers and Code Owners and establishes a recurring governance review cadence. As a governance policy change, it requires a formal
organization-balanced vote under our governance rules.

The vote applies to commit b899145.

Affiliation Eligible Maintainers Position
━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━
Postman @lbroudoux, @yada Pending
───────────── ────────────────────── ──────────
AXA France @SebastienDegodez Pending

Please reply with:

• +1 — approve
• 0 — abstain
• -1 — oppose, with an explanation

The vote opens on September 11, 2026 and remains open through September 25, 2026, unless it can be closed early because the outcome can no longer change.

Approval requires both eligible organizational votes.

[yada]

My vote: +1 (binding)

[SebastienDegodez]

My vote: +1 (binding)