[release/v7.6] Add markdown link verification for PRs

[TravisEz13]

Backport of #26219 to release/v7.6

Triggered by @TravisEz13 on behalf of @TravisEz13

Original CL Label: CL-Test

/cc @PowerShell/powershell-maintainers

Impact

REQUIRED: Choose either Tooling Impact or Customer Impact (or both). At least one checkbox must be selected.

Tooling Impact

• Required tooling change
• Optional tooling change (include reasoning)

Adds markdown link verification to PR workflows on release/v7.6 branch. This ensures documentation quality and catches broken links before they are merged. Critical for maintaining documentation integrity on the release branch.

Customer Impact

• Customer reported
• Found internally

Regression

REQUIRED: Check exactly one box.

• Yes
• No

This is not a regression.

Testing

Original PR added comprehensive testing via the new markdown link verification action. Backport verified by checking that all new files are present and the workflow is correctly integrated into the release branch CI/CD pipeline.

Risk

REQUIRED: Check exactly one box.

• High
• Medium
• Low

Low risk as this adds new CI/CD infrastructure (GitHub Actions) without modifying existing code. The action only runs on markdown files and provides additional verification. No changes to runtime code, cmdlets, or PowerShell functionality.

[Copilot]

Pull Request Overview

This PR backports markdown link verification infrastructure from the main branch to the release/v7.6 branch. It adds a comprehensive GitHub Actions workflow and composite action to automatically verify all links in markdown files, helping maintain documentation quality by catching broken links before they are merged.

Key Changes:

• New workflow to verify markdown links on PRs, pushes, and scheduled runs
• Custom GitHub composite action using PowerShell and Markdig for link parsing and verification
• PowerShell parameter naming conventions instruction file for GitHub Copilot

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
.github/workflows/verify-markdown-links.yml	Workflow definition that triggers link verification on markdown file changes
.github/actions/infrastructure/markdownlinks/action.yml	Composite action that orchestrates link verification and outputs metrics
.github/actions/infrastructure/markdownlinks/Verify-MarkdownLinks.ps1	Core PowerShell script that verifies HTTP/HTTPS and local file links
.github/actions/infrastructure/markdownlinks/Parse-MarkdownLink.ps1	PowerShell script that parses markdown files using Markdig to extract links
.github/actions/infrastructure/markdownlinks/README.md	Documentation for the markdown link verification action
.github/instructions/powershell-parameter-naming.instructions.md	GitHub Copilot instruction file for PowerShell parameter naming conventions

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