adding attributes to regulate QUOTE_TAGS

[JurTam]

Dear fellow Asciidoctors :).

I've come across a few epub reading apps that render different font thicknesses and styles based on HTML tags, not strictly adhering to CSS-set parameters.
For example, Moon Reader Plus for Android, makes <strong> text bold by adding a border around each character, while for <b>, it uses a true bold font from the selected family.
Similarly "<em>phasized" text is created by slanting original font characters sideways, while <i> makes the reader use the actual italic font.
I also remember my friend's Kobo reader doing something similar.
That can be quite a nuisance, for example when regular text ends up looking exactly the same or almost the same as the one in bold or italics.

For my own use, I just modified the converter.rb file by replacing <strong></strong> and <em></em> with <b><b/> and <i></i>, respectively, in the "QUOTE_TAGS" section.
I think it would be usable though, for on the fly changes, to include attributes that allow modifying the generated HTML tags.
For example, :strong-tag:, with :strong-tag: strong being used by default.

I know the desired effect can be achieved manually, by using pass:[<b>]some text blah blah blahpass:[</b>] for example, but it's not really the Asciidoctor way, is it :).

I'd love to help, but I'll need some pointers as to how Asciidoctor's attributes are implemented.
Thanks, All the best, JT