In order to add arbitrary text to your help string, use the following form:
(text [OPTIONS…])
OPTIONS are key/value pairs. The following OPTIONS are currently available.
:contents ¶The actual text string. Try to make proper sentences when adding arbitrary text. You can use explicit newline characters in your text if you really want to go next line, but in general, you should not worry about the formatting because the themes are here to do so. In particular, don’t finish your text with a newline. This would break potential theme specifications.
:hidden ¶When non-nil, the text won’t appear in the help string. Hidden
texts can still be displayed individually though (see Help).