Update cpp-type-system-modern-cpp.md

[drvoss]

Add semicolon

[prmerger-automator]

@drvoss : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[opbld31]

Learn Build status updates of commit ae725db:

✅ Validation status: passed

File	Status	Preview URL	Details
docs/cpp/cpp-type-system-modern-cpp.md	✅Succeeded

For more details, please refer to the build report.

Note: Broken links written as relative paths are included in the above build report. For broken links written as absolute paths or external URLs, see the broken link report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[colin-home]

@drvoss Looks like a worthy addition to the example. Thanks!