Add importing html and save it to Article

Additionally defines a wizard logic which is partially unused yet.

lib/outlook_web.ex

@@ -86,6 +86,7 @@ defmodule OutlookWeb do
       import Phoenix.HTML
       # Core UI components and translation
       import OutlookWeb.CoreComponents
+      import OutlookWeb.HtmlTreeComponent
       import OutlookWeb.Gettext
 
       # Shortcut for generating JS commands