Merges code and deindents

Since there's no difference now after 6.d. Refs #2632. Also eliminates a reference to 6.d.PREVIEW refs #2687

doc/Language/terms.pod6

@@ -256,7 +256,7 @@ our constant @foo = 1, 2, 3;
 
 I<NOTE: if you're using the Rakudo compiler, you need version 2018.08 or
 newer for type constraints and auto-coercion on constants to be
-available. Auto-coercion on %-sigiled constants requires 6.d>
+available. Auto-coercion on %-sigiled constants requires 6.d>.
 
 An optional type constraint can be used, in which case the use
 of scope declarator is required:
@@ -294,26 +294,23 @@ auto-coercion of the value if it does not pass the implied typecheck.
 The C<@>-sigiled constants will coerce using method L<cache|/routine/cache> and
 C<%>-sigiled constants coerce using method L<Map|/type/Map>.
 
-    =begin code
-    constant @foo = 42;
-    @foo.perl.say; # OUTPUT: «(42,)»
+=begin code
+constant @foo = 42;
+@foo.perl.say; # OUTPUT: «(42,)»
 
-    constant @bar = [<a b c>];
-    @bar.perl.say; # OUTPUT: «["a", "b", "c"]»
-    =end code
+constant @bar = [<a b c>];
+@bar.perl.say; # OUTPUT: «["a", "b", "c"]»
 
-    =begin code :solo
-    use v6.d.PREVIEW;
-    constant %foo = <foo bar>;
-    %foo.perl.say; # OUTPUT: «Map.new((:foo("bar")))»
+constant %foo = <foo bar>;
+%foo.perl.say; # OUTPUT: «Map.new((:foo("bar")))»
 
-    constant %bar = {:10foo, :72bar};
-    %bar.perl.say; # OUTPUT: «{:bar(72), :foo(10)}»
+constant %bar = {:10foo, :72bar};
+%bar.perl.say; # OUTPUT: «{:bar(72), :foo(10)}»
 
-    # Pair is already Associative, so it remains a Pair
-    constant %baz = :72baz;
-    %baz.perl.say; # OUTPUT: «:baz(72)»
-    =end code
+# Pair is already Associative, so it remains a Pair
+constant %baz = :72baz;
+%baz.perl.say; # OUTPUT: «:baz(72)»
+=end code
 
 For convenience and consistency reasons, you can use the
 L«binding operator (C<:=>)|/routine/:=» instead of the assignment operator,