Create content for "Hero" (Headline on homepage)

This is about the text displayed in the "hero" on the start page just below "AsciiDoc Working Group"

The current preview: https://eclipsefdn-asciidoc-wg.netlify.app/

Content is the "tagline" in the following file: https://github.com/EclipseFdn/asciidoc.eclipse.org/blob/main/content/_index.adoc

This can be taken from the charter.