add info on doc sorting in this directory

Author: tbrowder

doc/Programs/README.md

@@ -1,3 +1,13 @@
+Attention contributers
+======================
+
+Files in this directory are sorted by file name to generate the index
+for the "Programs" tab (in contrast to the other tabs which are
+indexed in order by each file's "=TITLE" entry).
+
+Source note
+===========
+
 The 00-running.pod file in this directory was copied from
 
   https://github.com/rakudo/rakudo/tree/nom/docs