Book structure

[Nowosad]

While updating the current draft to quarto and tmap4, I made several changes to the book, including changing the order of the chapters, adding book parts, creating more chapters, moving content, etc. I think it is still not perfect and probably some better structure exist.

For example, I've been thinking about moving spatial data part as an appendix (along with a second appendix with a basics for data processing (e.g., cropping, simplifing, etc.). I've been also thinking of moving CRS stuff into its own, more advanced chapter.

Any suggestions, comments, ideas are welcome -- @mtennekes @olivroy