Clarify and Formalize Steering Committee Membership Application Process

### Describe the bug

## Summary

The Microcks governance model introduces a Steering Committee (SC) as a key component for strategic oversight and adopter representation. However, while the existence and purpose of the SC are documented, the process for becoming a member is not clearly defined or easily discoverable.

This issue proposes clarifying and formalizing a transparent, documented policy for Steering Committee membership applications, aligned with the existing governance model.

## Context

The current governance documentation establishes that:

- The Steering Committee is responsible for strategic direction, sustainability, and representing adopters
- Detailed guidelines for composition and election are referenced in a Steering Committee charter

However:

- There is no clearly documented **application or nomination process** available to the broader community
- It is unclear how new members are proposed, evaluated, and selected
- There is no standardized guidance for prospective candidates

This creates ambiguity for contributors and adopters who may want to participate in governance.

## Problem

Without a clearly defined and public process:

- Membership decisions may appear opaque or ad hoc
- Potential candidates lack guidance on how to engage
- The governance model may not scale as the community grows

## Proposal

Extend or complement the existing Steering Committee documentation with a dedicated section (or standalone document) that explicitly defines:

### 1. Path to Membership
- Whether membership is nomination-based, application-based, or invitation-based
- Who can nominate (self, maintainers, community, adopters)

### 2. Eligibility Criteria
- Expected level of contribution or adoption
- Representation expectations (for example, adopters vs contributors)
- Alignment with project values and Code of Conduct

### 3. Application / Nomination Process
- Where and how to apply (GitHub issue, PR, discussion, etc.)
- Required information (background, contributions, intent)
- Timeline and review cadence

### 4. Evaluation and Selection
- Voting or decision-making mechanism
- Required quorum or approval threshold
- Role of existing SC members vs maintainers

### 5. Transparency
- How decisions are communicated publicly
- Whether applications and discussions are open or private

## Acceptance Criteria

- A clearly documented membership process is added to the Steering Committee governance docs
- The process is actionable and discoverable by the community
- Roles and responsibilities in the selection process are unambiguous

## Additional Context

This proposal does not aim to redefine the Steering Committee charter, but to **operationalize it** by making the path to membership explicit, transparent, and scalable as the Microcks community continues to grow.

### Attach any resources that can help us understand the issue.

_No response_

Start by locating the existing governance model and referenced Steering Committee charter, then compare their membership guidance with the gaps listed in this issue. Define the application or nomination path, eligibility, evaluation, selection, and transparency rules; the work is done when the resulting documentation is actionable, discoverable, and unambiguous about roles and decisions.

Written by the indexing model from the issue text.