Fix a couple of typos

doc/Type/Mu.pod6

@@ -293,9 +293,9 @@ case we are declaring this C<new> method simply to avoid the extra syntax of
 using pairs when creating the object. C<self.bless> returns the object, which is
 in turn returned by C<new>.
 
-However, in general, implementing a customized C<new> method might be the best
+However, in general, implementing a customized C<new> method might not be the best
 way of initializing a class, even more so if the default constructor is
-disabled, since  it can make harder to correctly initialize the class from a
+disabled, since it can make it harder to correctly initialize the class from a
 subclass. For instance, in the above example, the C<new> implementation takes
 two positional arguments that must be passed from the subclass to the superclass
 in the exact order. That is not a real problem if it's not documented, but take