Add script to generate book PDF

.gitignore

@@ -1,4 +1,77 @@
-_site
-.directory
+book.pdf
+
+# Created by https://www.gitignore.io/api/ruby,linux,jekyll
+
+### Jekyll ###
+_site/
+.sass-cache/
 .jekyll-metadata
-*~*
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### Ruby ###
+*.gem
+*.rbc
+/.config
+/coverage/
+/InstalledFiles
+/pkg/
+/spec/reports/
+/spec/examples.txt
+/test/tmp/
+/test/version_tmp/
+/tmp/
+
+# Used by dotenv library to load environment variables.
+# .env
+
+## Specific to RubyMotion:
+.dat*
+.repl_history
+build/
+*.bridgesupport
+build-iPhoneOS/
+build-iPhoneSimulator/
+
+## Specific to RubyMotion (use of CocoaPods):
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+#
+# vendor/Pods/
+
+## Documentation cache and generated files:
+/.yardoc/
+/_yardoc/
+/doc/
+/rdoc/
+
+## Environment normalization:
+/.bundle/
+/vendor/bundle
+/lib/bundler/man/
+
+# for a library or gem, you might want to ignore these files since the code is
+# intended to run in multiple environments; otherwise, check them in:
+# Gemfile.lock
+# .ruby-version
+# .ruby-gemset
+
+# unless supporting rvm < 1.11.0 or doing something fancy, ignore this:
+.rvmrc
+
+# End of https://www.gitignore.io/api/ruby,linux,jekyll

utils/convert_to_pdf.sh

@@ -0,0 +1,10 @@
+---
+---
+#!/bin/sh
+
+oldCWD="$PWD"
+cd $(dirname $0)
+cd ../en/
+
+wkhtmltopdf --print-media-type {% for link in site.data.links_en %}{% if link.link %}{{ link.link }} {% endif %}{% endfor %} out.pdf
+mv out.pdf $oldCWD/book.pdf