Fix inconsistent heading levels in copilot-instructions.md

[Copilot]

Description

Summary of changes:

• Fixed inconsistent markdown heading levels in .github/copilot-instructions.md
• Changed section headings from # to ## for consistency with document structure
• Added ## prefix to "Common Patterns" and ### to "Network Controller REST Parameter Pattern" subsection
• Improved list formatting for logging levels (added bold formatting and proper bullet syntax)

All sections now follow consistent hierarchy:

• # for document title only
• ## for top-level sections
• ### for subsections

Change type

• Bug fix (non-breaking change)
• Code style update (formatting, local variables)
• New Feature (non-breaking change that adds new functionality without impacting existing)
• Breaking change (fix or feature that may cause functionality impact)
• Other

Checklist:

• My code follows the style and contribution guidelines of this project.
• I have tested and validated my code changes.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.