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.

1993/dgibson/README.md

@@ -22,7 +22,7 @@ make all
 ```
 
 where:
-\
+
 `datafile` is the initial pattern (default: [dgibson.data1](dgibson.data1))