Update arabian localization with latest merged

Created by: el00ruobuob

Since #741 #756 and #767 were merged, a few things have to been added.

There are new variables to translate in ar.yml @3b7ameed

Created by: el00ruobuob

Sorry @erciccione, those were merged so fast i haven't got the time to warn before #800 was merged.

Created by: el00ruobuob

Just revert those end of line removal coming from nowhere on ar.yml.

Created by: el00ruobuob

As @BlackLotus64 mention in IRC monero-localisation channel, building the site actually fail without the new guide added for Arabian. A quick merge will be helpful here @luigi1111. Call for reviewers @erciccione @rehrar @maxXor @mattcode55