Initialize theme on existing content folder

Currently, the wizard triggered by yarn create @eclipsefdn/revealjs-solstice create a sub-folder using the project name as the folder and fill it with the skeleton of a demo project containing a slide.adoc example.

Considering that this theme will be mainly applied to existing *.adoc content, can the wizard be adapted to apply the theme to an existing folder, with an optional flag -c/--create to create a fresh folder, keeping the current behavior ?