The appendix's supplemental content is categorized as follows:
Setup sections detail development environment configuration and usage.
Inventory sections catalog resources. Like tools covered and other books recommended.
Foundations sections provide brief, optional introductions to key concepts. To accommodate readers of different backgrounds.
Misc (miscellaneous) sections cover topics that, while important, don't fit naturally within the arc of the book.
Appendix sections aren't just a tack-on - they're written with the same care and effort as the main chapters.