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.

1990/tbr/README.md

@@ -1,9 +1,9 @@
 # Best Utility
 
-Byron Rakitzis	         
+Byron Rakitzis\
 US
 
-Sean Dorward   
+Sean Dorward\
 US