little fix to support arabic in pdf.

[Saifallak]

Overview

Me and #34 and many others in the community using the Arabic language need to use PDF export.

Proposal

using the library https://github.com/khaled-alshamaa/ar-php we can modify the outputted HTML to support our language.

how? if ArPHP is installed on the system it will use it, by: class_exists('ArPHP\I18N\Arabic')

why it's not required in composer? I didn't require it in Composer because i don't think everybody needs Arabic support.

BTW: if you think this should be installed on every project just require it also, I think it would be great if we can mention it in the readme, but not sure.

Linked Issues & PRs

this helps #75 and follows #76 to support more locales (eg. Arabic) and for sure fixes #34