cleanup winner README.md files

Fixed cases where there was a bad trailing backslash.

Improved a few cases where a code block was needed
to highlight some text.

Changed a few cases where a code block needed to
declared as, say, a sh code block.

Fixed a few cases where the winner information was not properly formatted.

Plus a few nits and clarifying text was added.

2000/dlowe/README.md

@@ -52,7 +52,9 @@ of the submitters hidden until all the prize winners have been selected.
 
 ### Usage
 
+```
 ./dlowe [file ...]
+```
 
 ### Synopsis