shink Rakudos ego slightly

doc/Type/Sub.pod6

@@ -81,7 +81,7 @@ to it (or even themselves) and we can apply traits to objects at runtime.
 
 There is a special trait for C<Sub>s called C<is default>. This trait is
 designed as a way to disambiguate C<multi> function calls that would normally
-throw an error because Rakudo would not know which one to use. This means that
+throw an error because the compiler would not know which one to use. This means that
 given the following two C<Sub>s, the one with the C<is default> trait will be
 called.