Given that it is a perfectly edited BOOK,
it’d be extremely helpful if we could study it from “inside”,
if we could open it as a master document… and study it…
I know that it is 450 pages (!!!), and it incorporates chapters and all,
but it would be great to have it…
OR… have a simplified version of it…
the next version of the Guide book could have references to that 
https://wiki.documentfoundation.org/Documentation/Publications
And also the Documentation page has “Download Source Files” links for all the recent entries.
wow, guys!
I remembered that that PHP site had the source code of the pages visible and was certain that this would not be far from what the Document Foundation can give, but I’m impressed, amazing!!!
thank you, I mean, for developing Libreoffice!! in this manner / and spirit
amazing!!!
Warning, though! The Writer Guide makes heavy use of tables in circumstances where I wouldn’t use them, i.e. to have an icon aside a warning or tip paragraph.
I personally use a frame anchored to paragraph so that the tip or warning is still part of the document main flow while text in a table is in a “secondary” flow. This may make differences when you create global lists spanning main flow, frames and/or tables (e.g. document outline).
But, once again, it depends on your goal. Both approaches are not direct replacement for each other and offer different formatting and layout possibilities. So learn the basics and after some practice study carefully the subtleties.
Writer has very smart features and allow really sophisticated book formatting, partly bridging the gap with DTP applications.