This commit allows a site to have generic text to appear at the top of
the site, underneath the header but above the topics. This is useful
because it allows a site maintainer to give more context or lead-ins to
the content available on the site. Since this might not be applicable
for all users, this is made an optional feature. If there is no index
file in `content/`, nothing will appear and the site will appear as it
does now.
Signed-off-by: Justin W. Flory (he/him) [UNICEF Innovation] <jflory@unicef.org>
E.g. "Contact" links to /contact by default or when defaultLanguageContent=en.
If the user selects any other language (e.g Es), the link points to "/es/contact".
The Call to Action button also points to the localized version of the Contact page.
