Elaborate a bit more on todo, skip, skip_rest

As spotted by japhb++

S24-testing.pod

@@ -55,6 +55,11 @@ All of the following functions are exported by default:
     flunk($desc?)
     diag($desc)
 
+    # skipping
+    todo($reason, $count = 1)
+    skip($reason, $count = 1)
+    skip_rest($reason?)
+
     # evaluates $cond in boolean context
     ok(Mu $cond, $desc?)
     nok(Mu $cond, $desc?)
@@ -143,6 +148,9 @@ they would die), and emits C<$count> SKIP markers in the TAP output.
 The C<skip_rest()> function can be called conditionally to C<skip($remaining)>
 all of the remaining tests.
 
+The C<todo()> and C<skip()> functions are generally automatically generated
+by some sort of source code fudging program.
+
 =head2 ok(), nok()
 
     sub ok(Mu $cond, $desc?) is export { ... }