<various>: Add cover page to PDFs.

SVG verified in:
https://validator.w3.org/check?uri=https%3A%2F%2Fraw.githubusercontent.com%2Fvoid-linux%2Fvoid-docs%2F219fa77873dc1cf1afbbeb187b7e76881b541241%2Fres%2Fhandbook-cover.svg&charset=%28detect+automatically%29&doctype=Inline&group=0

Closes: #495 [via git-merge-pr]

Author: flexibeast

.gitignore

@@ -2,3 +2,4 @@ book/
 mandoc/
 res/void-docs
 res/void-docs.1
+res/handbook-cover.png

README.md

@@ -17,6 +17,7 @@ Void packages:
 - `texlive`
 - `perl`
 - `perl-JSON`
+- `librsvg-utils`
 
 In order to build and install these files, set the `PREFIX` and `DESTDIR`
 environment variables to appropriate values and run `res/build.sh` followed by

res/README.md

@@ -0,0 +1,2 @@
+The original cover variants, as suggested by @argosatcore on GitHub,
+are available in the `handbook-cover-variants.svg` file.

res/build.sh

@@ -28,8 +28,25 @@ sed -e "s,@PREFIX@,$PREFIX," res/void-docs.in > res/void-docs
 sed -e "s,@PREFIX@,$PREFIX," res/void-docs.1.in > res/void-docs.1
 
 # Build PDF
+
 echo "Building PDF"
+
+## Temporarily add OpenType version of Latin Modern to font cache.
+
+mkdir -p ~/.fonts
+TMP_FONTDIR=$(mktemp -d -p ~/.fonts)
+cp /usr/share/texmf-dist/fonts/opentype/public/lm/* $TMP_FONTDIR
+fc-cache
+
+## Create cover page using Latin Modern text.
+
+rsvg-convert \
+    --dpi-x 300 \
+    --dpi-y 300 \
+    res/handbook-cover.svg > res/handbook-cover.png
+
 ## Letter version
+
 pdflatex \
     -output-directory=book/latex/ \
     -jobname=handbook-letter \
@@ -40,7 +57,9 @@ pdflatex \
     -jobname=handbook-letter \
     book/latex/handbook.tex \
     >/dev/null
+
 ## A4 version
+
 sed -ie "s/\\documentclass\[letterpaper\]{article}/\\documentclass[a4paper]{article}/" \
     book/latex/handbook.tex
 pdflatex -output-directory=book/latex/ \
@@ -51,3 +70,8 @@ pdflatex -output-directory=book/latex/ \
          -jobname=handbook-a4 \
          book/latex/handbook.tex \
          >/dev/null
+
+## Remove temporary font directory
+
+rm -rf $TMP_FONTDIR
+fc-cache