fix improper use of whitespace in README.md files

The use of the markdown trailing whitespace to indicate
line break should NOT be done when the following line is empty.

This removes such improper use of whitespace in README.md files.

2006/monge/README.md

@@ -170,7 +170,7 @@ changing the definitions of `W`, `H` and `I` at the beginning of the code.
 - There should be some way to switch from Mandelbrot to Julia with chosen
   parameter.
 
-### Spoiler 
+### Spoiler
 
 Sure, I don't want to deprive you of the pleasure of digging
 into the infernal mess created by my corrupted mind (writing