convert INABIAF headers in README.md to a Jargon File quote

We introduce a bit of fun, while specifying that something
is "supposed to happen".

NOTE: There is no need to change the INABIAF STATUS.  The use
there is perfectly fine.

2001/dgbeards/README.md

@@ -44,10 +44,15 @@ make alt
 Use `dgbeards.alt` as you would `dgbeards` above. Can you find a flaw in this
 version that the author did not note?
 
-## INABIAF - it's not a bug it's a feature! :-)
-
 This game crashes if it loses.
 
+This is supposed to happen.  As is written in the
+[The Jargon File](http://catb.org/jargon/html/F/feature.html):
+
+```
+That's not a bug, that's a feature.
+```
+
 
 ### Try: