Create a repository document describing criteria for bringing fixes into an LTS (Long-Term Servicing/Support) release branch in PowerShell, in response to discussion on PR #26167.

Requirements:

• Target repository: PowerShell/PowerShell
• Base branch: master
• Add a new Markdown doc at docs/release/LTS-servicing-criteria.md.
• The document should:
  • Explain the purpose of LTS branches and the servicing philosophy (stability-first).
  • Clearly state that while the community can propose backports, Microsoft makes the final decision on what goes into LTS servicing branches/patch releases.
  • Define the “bar” for LTS fixes in practical terms (security fixes; high-impact servicing fixes designed to minimize impact; strong presumption against features/behavior changes).
  • Include a checklist/template contributors can use when requesting an LTS backport (customer impact, regression info, severity, risk assessment, testing, links to issues/PRs, whether fix is already in the newest supported non-LTS/STS release).
  • Clarify that low-risk alone is not sufficient; it must also be sufficiently impactful.
  • Clarify expectations about sequencing (e.g., land in current supported release line first where applicable) and any rationale.
  • Provide links to official Microsoft documentation for PowerShell support lifecycle / LTS servicing policy.
  • Use clear, neutral language suitable for a public OSS repo.

Deliverables:

• Commit adding the new doc.
• If there is an existing release/backport documentation index (e.g., a docs README or release-process doc), add a link to this new document so it’s discoverable.

Notes:

• Keep it aligned with public Microsoft guidance: “Updates to an LTS release only contain critical security updates and servicing fixes designed to minimize impact on existing workloads.”
• Do not include confidential/internal-only criteria; acknowledge that there may be internal requirements not publicly documented.