Clarify behavior of raku method on type objects

Author: stoned

doc/Type/Mu.pod6

@@ -186,7 +186,7 @@ near future. Use C<.raku> instead.
     multi method raku(Mu:D:)
 
 For type objects, returns its name if C<.perl> has not been redefined from
-Mu, or calls C<.perl> o the name of the type object otherwise.
+Mu, or calls C<.perl> on the type object otherwise.
 
     say Str.raku;          # OUTPUT: «Str␤»