One way of addressing a formatto in create-cli.rakudoc (#4469)

There's a segment in the doc which has two consecutive `=item` lists. It's clear to me the second one is supposed to correspond to the first one, with three items in the second list to match the first list. But the second just had two items. This PR just fixes that basic mistake, and is a minimalist approach to addressing that basic problem.

However, t seems to me the two lists would be better as a single list of three items, or perhaps better, a table. Rather than write that (more complicated) PR I've decided to wait for responses to this simpler solution.

Author: raiph

doc/Language/create-cli.rakudoc

@@ -247,7 +247,7 @@ Here's how it works; with Raku distinguishing between three types of options:
 And here's the signature that produces each type of argument:
 
 =item Boolean options: A L<C<Bool>|/type/Bool> type constraint.
-    Options with a mandatory argument: A type that does not
+=item Options with a mandatory argument: A type that does not
     L<C<.ACCEPT>|/routine/ACCEPTS> a L<C<Bool>|/type/Bool>.
 =item Options with an optional argument: A type that C<.ACCEPTS> a
    C<True> (because passing an option without an argument is equivalent