Surface the new Pester migration skills in the docs

[nohwnd]

Context

Two self-contained Copilot skills (awesome-copilot SKILL.md format) were created for Pester. This issue tracks surfacing them from the docs site later — e.g. a callout/page that points users at the skills, and/or a short "AI-assisted migration" section in the migration guides.

Both are grounded entirely in this repo's migration and usage docs, and both are currently experimental PRs against github/awesome-copilot.

Skill 1 — pester-migration (version upgrades)

Upgrades a Pester suite across major versions — runtime, mocks, config. A single router skill covering all three jumps v3→v4, v4→v5, v5→v6, with the shared detect → baseline → fix → verify workflow in SKILL.md and per-version detail in references/.

• Live PR: Add pester-migration skill (experimental) github/awesome-copilot#2163 — Add pester-migration skill (experimental) (open)
• Original PR in this repo (closed, kept for reference): Add Pester migration skill (awesome-copilot format) #389 — closed because the skill belongs in github/awesome-copilot, not the docs-site repo. Branch preserved: nohwnd-pester-migration-skills.

Files (on branch nohwnd-pester-migration-skills):

• SKILL.md — router: version detection, install commands, migrate-one-major-at-a-time workflow, scope/difficulty table, inline cheat sheets, safety rules
• references/v3-to-v4.md — Should -Be / FileContentMatch renames, automated-script links
• references/v4-to-v5.md — the hard jump: Discovery/Run two-phase model, BeforeAll, $PSScriptRoot, BeforeDiscovery/-ForEach, mock scoping, Invoke-Pester → New-PesterConfiguration map
• references/v5-to-v6.md — every v6 breaking change as symptom → fix; optional Should-* note

Skill 2 — pester-should-migration (assertion syntax)

A companion to skill 1. Covers the separate, optional move from the classic v5 Should -Be syntax to the new v6 Should-* assertions (hyphen, no space) — e.g. Should -Be → Should-Be, Should -Not -BeNullOrEmpty → Should-NotBeNull. In Pester 6 the classic Should -Be keeps working, so this is independent of any version bump.

• Live PR: Add pester-should-migration skill (experimental) github/awesome-copilot#2164 — Add pester-should-migration skill (experimental) (open)

Files (on branch nohwnd:add-pester-should-migration-skill):

• SKILL.md — when to use, a 5-step procedure (find → map → check gotchas → verify → optionally enforce Should.DisableV5), a common-conversions table, and 7 behavioral gotchas
• references/assertion-map.md — full operator-by-operator mapping with before/after examples and workarounds for operators with no direct equivalent

Follow-up

• Once awesome-copilot#2163 and #2164 merge, decide how to surface both skills from the docs site (link out to the awesome-copilot skills, and/or add a short "AI-assisted migration" section to the v5→v6 migration guide).
• Keep both skills in sync with the migration / assertion docs as v6 stabilizes.