Revert dd test and okay yyyy-mm-dd examples

It was suggested that the yyyy-mm-dd exceptions be okayed and the
modifications testing for it be reverted. In this case, it is better to
manually ok the handful of exceptions than work the exceptions into the
test, making it more cluttered and obscuring the intent.

Author: jstuder-gh

doc/Type/Dateish.pod6

@@ -186,8 +186,10 @@ Defined as:
 
 Returns the date in C<YYYY-MM-DD> format (L<ISO 8601|https://en.wikipedia.org/wiki/ISO_8601>)
 
+=begin code :ok-test<dd>
     say Date.new("2015-11-15").yyyy-mm-dd;   # OUTPUT: «2015-11-15␤»
     say DateTime.new(1470853583).yyyy-mm-dd; # OUTPUT: «2016-08-10␤»
+=end code
 
 =head2 method daycount
 

doc/Type/X/Temporal/InvalidFormat.pod6

@@ -10,10 +10,11 @@ class X::Temporal::InvalidFormat does X::Temporal is Exception { }
 This exception is thrown when code tries to create a C<DateTime> or C<Date> object
 using an invalid format.
 
-=for code
-my $dt = Date.new("12/25/2015");
-CATCH { default { put .^name, ': ', .Str } };
-# OUTPUT: «X::Temporal::InvalidFormat: Invalid Date string '12/25/2015'; use yyyy-mm-dd instead␤»
+=begin code :ok-test<dd>
+    my $dt = Date.new("12/25/2015");
+    CATCH { default { put .^name, ': ', .Str } };
+    # OUTPUT: «X::Temporal::InvalidFormat: Invalid Date string '12/25/2015'; use yyyy-mm-dd instead␤»
+=end code
 
 =head1 Methods