add references to Q syntax

Author: schultzdavid

doc/Language/create-cli.rakudoc

@@ -500,6 +500,11 @@ If no multi candidate of C<MAIN> is found for the given command line
 parameters, the sub C<USAGE> is called. If no such method is found,
 the compiler will output a default usage message.
 
+In the following example, we print a custom usage message via
+a L<Q string|/language/quoting> 
+(with the C<:c|/language/quoting#Heredocs:_:to> flag enabling interpolation of curly braces,
+and the C<:to|/language/quoting#Heredocs:_:to> flag for stating it all as a heredoc):
+
     #|(is it the answer)
     multi MAIN(Int $i) { say $i == 42 ?? 'answer' !! 'dunno' }
     #|(divide two numbers)