chore: add copilot instructions and agent setup steps workflow

[FidelusAleksander]

Summary

Changes

Closes:

Task list

• For workflow changes, I have verified the Actions workflows function as expected.
• For content changes, I have reviewed the style guide.

[Copilot]

Pull Request Overview

This PR introduces a GitHub Actions workflow for setting up the Copilot agent environment and adds a markdown guide for Copilot-related instructions and repository standards.

• Add copilot-setup-steps.yml workflow to install dependencies and prepare Node.js
• Add copilot-instructions.md to outline code standards, repo structure, and quality guidelines

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
.github/workflows/copilot-setup-steps.yml	New workflow for checkout, Node.js setup, and npm install
.github/copilot-instructions.md	Markdown guide for code standards and repository layout

Comments suppressed due to low confidence (2)

.github/copilot-instructions.md:1

• The header doesn’t match the file name. Consider renaming it to 'Copilot Instructions' or updating the file name to 'text-variables.md' to align with the content.

# GitHub Action: Text Variables

.github/workflows/copilot-setup-steps.yml:21

• Pin this action to a specific patch version (e.g., @v4.6.0) or a commit SHA to avoid unexpected breaking changes from future minor/major updates.

        uses: actions/checkout@v4