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.

2005/giljade/README.md

@@ -1,7 +1,7 @@
 # Best 2D puzzle
 
-Gil Dogon  
-Israel  
+Gil Dogon\
+Israel\
 <gil_jade@netvision.net.il>