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/sds/README.md

@@ -1,7 +1,7 @@
 # Best Abuse of Indentation
 
-Stephen Sykes  
-Finland  
+Stephen Sykes\
+Finland\
 <https://web.archive.org/web/20160316092728/http://www.stephensykes.com/>
 
 ## To build: