Upgrade the manual to docbook 5.0

To upgrade the manual:
sudo dnf install -y docbook5-schemas
xsltproc --output index-new.docbook /usr/share/xml/docbook5/stylesheet/upgrade/db4-upgrade.xsl index.docbook
xsltproc --output legal-new.xml /usr/share/xml/docbook5/stylesheet/upgrade/db4-upgrade.xsl legal.xml

To validate the manual:
xmllint --noout --relaxng /usr/share/xml/docbook5/schema/rng/5.0/docbook.rng help/C/index.docbook
jing /usr/share/xml/docbook5/schema/rng/5.0/docbook.rng help/C/index.docbook
yelp-check validate help/C/index.docbook

To view the manual:
yelp file:///full_path/index.docbook

Note: docbook5-schemas should be installed in your system in order to view the manual (DEPENDENCY)