replace trailing whitespace with blackslash in README.md

As an alternative to the markdown trailing whitespace as a line
break, we use a trailing blackslash as a markdown line break.

2004/vik1/README.md

@@ -1,9 +1,9 @@
 # Best X11 Game
 
-Daniel Vik   
-US  
-<daniel@vik.cc>  
-<https://www.vik.cc/>  
+Daniel Vik\
+US\
+<daniel@vik.cc>\
+<https://www.vik.cc/>\
 <http://danielvik.com/>
 
 ## To build: