rename chapter 2, add viz draft, add chapter summary paragraph

[kweav]

This PR addresses

• part of Issue Rename chapters #32, renaming chapter 2
• Issue another visual for emphasis for chapter 2 conclusion #13 adding a visualization draft for this emphasis block, specifically pointing out that while a visualization is worth 1000 words, it still needs words to be effective
• adds a summary paragraph to the chapter

[github-actions]

OTTR Check Results

Summary

• Spelling check: ❌ FAILED (13 errors found, threshold: 0)
• URL check: ✅ PASSED (0 errors found, threshold: 0)

⚠️ Some Checks Failed Click here to download detailed error reports

Last Updated: 2026-01-09-17:49:49

[github-actions]

Re-rendered previews from the latest commit:

• 👀 Quick preview of course website here *
• 🔬 Comprehensive download of the course website here
• Download the .docx file

* note not all html features will be properly displayed in the "quick preview" but it will give you a rough idea.

Updated at 2026-01-09 with changes from the latest commit 1d2ba3d

[kweav]

Note spell check handled in PR #31