Highlight qdoc keywords and lines

Hi Gerrit team!

Could you please add highlighting for qdoc keywords like \class, \fn, \brief, etc. to the diff viewers?

While at it you might want to highlight complete lines starting with "\section1", "\section2" and so on. Bonus points if the highlighting gets less and less prominent the higher the number.

That would make reviewing documentation changes so much easier

Best Regards,
Tobias