Enabling more strong emphasis inside the quote

[alexandreaquiles]

If we put more than one Markdown **strong emphasis** into the quote, makes it fail to "enrich" content.

Example:

> **Info** Text inside a box that accepts *italic* and **bold** emphasis.

Without the changes in this pull request, it renders:

With improvements on selection of the config text and on css, it renders:

I've also tested with several strong and regular emphasis and it worked.

[erixtekila]

Thanks for the fix.