Move 2014/vik bug notice from years to README.md

As the years.html file will be generated with a tool (yet to be written)
having the bug notice will (greatly)? complicate the generation. Thus
the bug notice (which I discovered when working on 2020/ferguson2) was
moved to 2014/vik/README.md.

But why? Because it is a good idea, I think, to note that although
mostly correct, there is a minor problem with it. I don't have a fix for
it but whether I ever look at that I do not know.

I also made a minor change in 2020/ferguson2/README.md: changed a full
stop to an exclamation mark as it seemed better.

2020/ferguson2/README.md

@@ -305,7 +305,7 @@ If I compile the 2014 entry and copy it to my local directory as
 $ echo TEST|./prog |./vik | mplayer -demuxer rawaudio -
 ```
 
-And you would hear Morse code of the Enigma output of 'TEST' (i.e. `KCWV`). Or
+And you would hear Morse code of the Enigma output of 'TEST' (i.e. `KCWV`)! Or
 perhaps not in this case. I'm not sure: I discovered a bug in that entry
 (Fedora, CentOS and macOS all affected).