fix more broken markdown links

Fixed stuff we broke by mistake, previously.

Ran `make www` to perform the above.

TODO: Fix stuff we broke by mistake doing the above.

TODO: Fix more broken markdown links.

2019/dogon/README.md

@@ -35,7 +35,7 @@ the program and the script.
 
 ## Judges' remarks:
 
-[1991/davidguy](../..//1991/davidguy/index.html),
+[1991/davidguy](../../1991/davidguy/index.html),
 [2011/blakely](../../2011/blakely/index.html), ...
 
 ...This entry likely concludes the IOCCC category "Cellular automata simulators";