reduce size of the binary package

Reduces the overall size of the binary package by 213.5 MB.

Make this a bit smaller, considering that we want to ship reform-handbook next to pocket-reform-handbook.

src/build-pdf-book.sh

@@ -45,7 +45,7 @@ xelatex --interaction=nonstopmode reform-handbook.tex
 xelatex --interaction=nonstopmode reform-handbook.tex
 
 # clean up
-mv reform-handbook.pdf ../build/
+ghostscript -sDEVICE=pdfwrite -dCompatibilityLevel=1.5 -dPDFSETTINGS=/printer -dNOPAUSE -dQUIET -dBATCH -sOutputFile=../build/reform-handbook.pdf reform-handbook.pdf
 rm -- _*.tex
 rm -- *.out
 rm -- *.log