The Banners section of the toolbar lets you insert page wide Information and Warning boxes.
Code like this
p(banner tip). This is an Information Box. It supports multiple lines of text and will automatically grow to fit its content. Use this for important information that you don't want your readers to miss.
will give you:
p(banner important). This a Warning Box. Use it for crucial information, to warn your reader for stuff that may go wrong.
will result in:
Thanks for your feedback.