Added a few code examples

Author: Jan-Olof Hendig

doc/Type/Supply.pod6

@@ -169,27 +169,39 @@ since the C<list> call.
 
 =head2 method grab
 
-    method grab(Supply:D: &process --> Supply:D)
+    method grab(Supply:D: &when-done --> Supply:D)
 
-Waits until the given supply is done.  It will then call the given process
-closure passing all of the values seen,  Then creates a supply to which all
-values returned from the process closure.
+Waits until the given C<Supply> is done.  It will then call the C<&when-done>
+closure passing all of the values seen,  Then creates a C<Supply> to which all
+values returned from the C<&when-done> closure are emitted.
+
+    my $s = Supply.from-list(4, 10, 3, 2);
+    my $t = $s.grab(&sum);
+    $t.tap(&say);           # OUTPUT: «19␤»
 
 =head2 method reverse
 
     method reverse(Supply:D: --> Supply:D)
 
-Waits until the given supply is done, then creates a supply to which all
+Waits until the given C<Supply> is done, then creates a C<Supply> to which all
 values seen are emitted in reverse order.
 
+    my $s = Supply.from-list(1, 2, 3);
+    my $t = $s.reverse;
+    $t.tap(&say);           # OUTPUT: «3␤2␤1␤»
+
 =head2 method sort
 
     method sort(Supply:D: &by? --> Supply:D)
 
-Waits until the given supply is done, then creates a supply to which all
+Waits until the given C<Supply> is done, then creates a C<Supply> to which all
 values seen are emitted in sorted order.  Optionally accepts a comparator
 L<Block|/type/Block>.
 
+    my $s = Supply.from-list(4, 10, 3, 2);
+    my $t = $s.sort();
+    $t.tap(&say);           # OUTPUT: «2␤3␤4␤10␤»
+
 =head1 Methods that return another Supply
 
 =head2 method from-list