contrib/examples/README: give an explanation of the status of these files

We attempt to give an explanation of the status of the files in this
directory.

Signed-off-by: jidanni <jidanni@jidanni.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/examples/README

@@ -0,0 +1,3 @@
+These are original scripted implementations, kept primarily for their
+reference value to any aspiring plumbing users who want to learn how
+pieces can be fit together.