Fixed formatting of code example and a few broken method links

doc/Type/Proc/Async.pod6

@@ -163,7 +163,7 @@ Note that you cannot call C<stdout> both with and without C<:bin> on the same
 object; it will throw an exception of type L<X::Proc::Async::CharsOrBytes> if
 you try.
 
-Use L«C<.Supply>|/type/Proc::Async#method_Supply>» for merged STDOUT and STDERR.
+Use L«C<.Supply>|/type/Proc::Async#method_Supply» for merged STDOUT and STDERR.
 
 =head2 method stderr
 
@@ -192,7 +192,7 @@ Note that you cannot call C<stderr> both with and without C<:bin> on the same
 object; it will throw an exception of type L<X::Proc::Async::CharsOrBytes> if
 you try.
 
-Use L«C<.Supply>|/type/Proc::Async#method_Supply>» for merged STDOUT and STDERR.
+Use L«C<.Supply>|/type/Proc::Async#method_Supply» for merged STDOUT and STDERR.
 
 =head2 method w
 
@@ -323,17 +323,17 @@ The C<:$translate-nl> option specifies whether new line endings should be
 translated for to match those used by the current operating system (e.g.
 C<\r\n> on Windows).
 
-    =for code
-    react {
-        with Proc::Async.new: «"$*EXECUTABLE" -e 'say 42; note 100'» {
-            whenever .Supply { .print }  # OUTPUT: «42␤100␤»
-            whenever .start {}
-        }
+=for code
+react {
+    with Proc::Async.new: «"$*EXECUTABLE" -e 'say 42; note 100'» {
+        whenever .Supply { .print }  # OUTPUT: «42␤100␤»
+        whenever .start {}
     }
+}
 
 It is an error to create both binary and non-binary
-L«C<.Supply>|/type/Proc::Async#method_Supply>». It is also an error
-to use both L«C<.Supply>|/type/Proc::Async#method_Supply>» and either
+L«C<.Supply>|/type/Proc::Async#method_Supply». It is also an error
+to use both L«C<.Supply>|/type/Proc::Async#method_Supply» and either
 L<stderr> or L<stdout> supplies.
 
 =head2 method close-stdin