Support HTML escape characters in site generator

[romain-grecourt]

HTML escapes are not working in the site navigation as well as the h1 title (top menu bar).

[tjquinno]

Using "Níma" (with the diacritical mark) in an .adoc file works, at least in generating an .html file with AsciiDoctorJ and when I build the site and render it locally.

(At least that's true in the main text body of a page with the quick test I tried.)

Ideally our site process would support HTML escape characters but, at least for the quick test case I tried, we can use the diacritical mark in-line.