Add AnchorKit meaningful change threshold guide

[El-swaggerito]

Description

Difficulty: Hard

Type: Documentation

Summary

Create a meaningful change threshold guide for AnchorKit PRs.

Current Behaviour

Some PRs may only include very small code changes without solving the underlying issue.

Expected Behaviour

The repo should explain that line count alone is not the standard, but the change must be complete, tested, and aligned with the issue requirements.

Suggested Implementation

Document examples of meaningful changes, insufficient changes, and how reviewers should assess scope.

Files or Areas Likely Affected

• packages/
• apps/
• examples/
• tests/
• docs/
• README.md
• .github/

Acceptance Criteria

• Meaningful change threshold guide is added.
• Guide explains that line count alone is not the only measure.
• Small but complete changes are distinguished from small incomplete changes.
• Insufficient examples are included.
• Reviewer assessment guidance is included.
• README links to the guide.

Additional Notes

This responds to concerns about very small merged PRs.

[ugoocreates-pixel]

So based on this description, with my experience, this shouldn't be an issue. I ask that you assign me to this issue

[grantfox-oss]

🦊 GrantFox — @ugoocreates-pixel has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #166)
2. Your PR will be reviewed by the Axionvera maintainers

Good luck! Track your progress on GrantFox.