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.

2014/birken/README.md

@@ -1,7 +1,7 @@
 # Best use of port 1701
 
 Michael Birken<br>
-<o__1@hotmail.com><br>  
+<o__1@hotmail.com><br>\
 <http://www.meatfighter.com/><br>
 <br>
 Alexander Prishchepov<br>