Document (Str, Code) and (Pair) subtest's multis

doc/Language/testing.pod6

@@ -66,7 +66,7 @@ the subtest.
 
 If a C<plan> is used, it is not necessary to denote the end of testing with
 C<done-testing>.
-
+s
 =item X<done-testing>
 
 Specify that testing has finished.  Use this function when you do not as yet
@@ -459,6 +459,23 @@ subtest {
 }, "Check Great Uncle Bulgaria";
 =end code
 
+You can also place description as the first positional argument, or use a C<Pair> with description as key and subtest's code
+as value. This can be useful for subtests with large bodies.
+
+=begin code
+subtest 'A bunch of tests', {
+    plan 42;
+    ...
+    ...
+}
+
+subtest 'Another bunch of tests' => {
+    plan 72;
+    ...
+    ...
+}
+=end code
+
 =head1 Skipping tests
 
 Sometimes tests just aren't ready to be run, for instance a feature might