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.

2019/duble/README.md

@@ -43,13 +43,17 @@ Open another window / terminal.
 
 Open more terminals and repeat...
 
-### INABIAF - it's not a bug it's a feature! :-)
-
-
 WARNING: if the file is deleted it might lock any session still in use. These
 will have to be killed from another shell session or by closing the terminal
 tab.
 
+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.
+```
+
 NOTE: this entry might leave sockets lying about in the current working
 directory which you'll have to delete manually. Here's an example in macOS:
 

2019/poikola/README.md

@@ -47,11 +47,16 @@ TZ=UTC48 make clobber prog
 ./prog 512 ./prog
 ```
 
-### INABIAF - it's not a bug it's a feature! :-)
-
 This program will not validate input so it might fail or get stuck if invoked
 erroneously.
 
+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.
+```
+
 
 ## Judges' remarks: