Update reference document Copilot review guidelines

[isra-fel]

Description

Added guideline for handling -ProgressAction parameter.
There's a limitation in v0.x of PlatyPS that could not handle the -ProgressAction parameter and leaves a placeholder.
We've added tools to handle that as part of the release process, so it doesn't make sense for copilot to leave review comments like this: https://github.com/Azure/azure-powershell/pull/29123/changes#r2747019780

Mandatory Checklist

• Please choose the target release of Azure PowerShell. (⚠️Target release is a different concept from API readiness. Please click below links for details.)

  • General release
  • Public preview
  • Private preview
  • Engineering build
  • No need for a release

• Check this box to confirm: I have read the Submitting Changes section of CONTRIBUTING.md and reviewed the following information:

• SHOULD update ChangeLog.md file(s) appropriately
  • Update src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md.
    • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header in the past tense.
  • Should not change ChangeLog.md if no new release is required, such as fixing test case only.
• SHOULD regenerate markdown help files if there is cmdlet API change. Instruction
• SHOULD have proper test coverage for changes in pull request.
• SHOULD NOT adjust version of module manually in pull request

[azure-client-tools-bot-prd]

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[Copilot]

Pull request overview

This PR adds a guideline to the Copilot review instructions to prevent automated review comments about -ProgressAction parameter placeholders in PowerShell help documentation. The change addresses a known limitation in PlatyPS v0.x tooling where the -ProgressAction parameter generates placeholder descriptions that are automatically removed during the build process.

Changes:

• Added guideline #2 to .github/instructions/reference-doc.instructions.md instructing reviewers to allow/ignore placeholder descriptions for the -ProgressAction parameter in help markdown files

[Copilot]

The wording "Allow placeholders for -ProgressAction" could be misleading. The actual behavior is that the build tooling (Remove-CommonParameterFromMarkdown in tools/BuildScripts/HelpMarkDown.psm1) automatically REMOVES the entire ProgressAction parameter section from help files during the build process. Consider revising to more accurately reflect that these placeholders are temporary and will be automatically removed, for example: "Ignore placeholders for -ProgressAction in PRs - the build tooling automatically removes this parameter section before release" or "Do not comment on -ProgressAction placeholders - they are automatically removed during the build process".

Suggested change

	2. **Allow placeholders for -ProgressAction** - there's a limitation in the tooling that the `-ProgressAction` parameter will have a placeholder description in the documents, e.g. `{{ Fill ProgressAction Description }}`. This is expected so do not leave review comments on that.
	2. **Ignore placeholders for -ProgressAction in PRs** - temporary placeholder descriptions for the `-ProgressAction` parameter (for example, `{{ Fill ProgressAction Description }}`) are expected, and the build tooling automatically removes this entire parameter section before release, so do not leave review comments on them.