[io grant] Document IO::Handle.put

doc/Type/IO/Handle.pod6

@@ -352,6 +352,25 @@ my $fh = open 'path/to/file', :w;
 $fh.printf: "The value is %d\n", 32;
 $fh.close;
 
+=head2 method put
+
+Defined as:
+
+    multi method put(**@text --> True)
+
+Writes the given C<@text> to the handle, coercing any non-L<Str> objects
+to L<Str> by calling L«C<.Str>|/routine/Str» method on them, and appending the
+value of L«C<.nl-out>|/type/IO::Handle#method_nl-out» at the end.
+
+Attempting to call this method when the handle is
+L<in binary mode|/type/IO::Handle#method_encoding> will result in
+C<X::IO::BinaryMode> exception being thrown.
+
+=for code :skip-test
+my $fh = 'path/to/file'.IO.open: :w;
+$fh.print: 'some text';
+$fh.close;
+
 =head2 method say
 
 Defined as: