[css-highlight-api-1] Example 2 lacks definition of a variable and inconsistent indentation between examples

[ffiori]

This issue is related to this draft: https://drafts.csswg.org/css-highlight-api-1

• In example 2 of the draft there's a variable named div used in setStart() and setEnd() which has never been defined.

• Minor detail: indentation in examples 1 and 2 is different from the others: <style> and <script> sections are not tabbed whereas they are in the others.

[ffiori]

@sanketj