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.

1988/dale/README.md

@@ -46,7 +46,7 @@ detail, see [thanks-for-fixes.md](/thanks-for-fixes.md).
 
 ## Judges' remarks
 
-This entry has a very twisted flow of control via recursion, iteration 
+This entry has a very twisted flow of control via recursion, iteration\
 and multi-processing.  Try to understand what is being done with the
 system calls.
 

1988/robison/README.md

@@ -45,7 +45,7 @@ This program shows that C has many unnecessary constructs, in fact
 only `while`,`--`, and `>=` are required.  (The two assignments at
 the beginning could be avoided if `atoi(3)` was rewritten with this
 new paradigm.)  Note that the lack of both the controversial `goto`
-and assignment statements makes the meaning crystal clear.  The current 
+and assignment statements makes the meaning crystal clear.  The current\
 ANSI committee should look into this practical simplification of C.
 
 ## Copyright and CC BY-SA 4.0 License:

1988/westley/README.md

@@ -1,6 +1,6 @@
 # Best layout
 
-Merlyn LeRoy (Brian Westley)  
+Merlyn LeRoy (Brian Westley)\
 US
 <http://www.westley.org>