fix: markdown rendering in tips and extract constants

[zealoushacker]

Summary

• Fix markdown rendering issues in Tip components by adding proper line breaks
• Extract dictionaries as module-level constants for better code organization
• Make code more pythonic with list comprehensions

Changes

Markdown Rendering Fixes

• Added missing line breaks after <Tip> and <Tip warning={true}> tags and before closing </Tip> tags
• This ensures markdown content (like bold text) renders properly inside tooltips
• Fixed 5 Tip components across 4 MDX files in unit3

Code Quality Improvements (per @elie's review)

• Extract type_mapping as TYPE_MAPPING constant (review comment)
• Extract default_templates as DEFAULT_TEMPLATES constant
• Convert get_pr_templates loops to list comprehensions (review comment)
• Remove unused imports (Dict, List, Any from typing)
• Fix unused exception variables

Files Modified

• 5 Python server files (build-mcp-server, github-actions-integration, slack-notification)
• 4 MDX lesson files (introduction, build-mcp-server, github-actions-integration, slack-notification)

Test plan

• Verify markdown renders correctly in Tip components
• Ensure all Python files run without import errors
• Confirm constants are properly used in all functions

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[burtenshaw]

LGTM