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.

1995/makarios/README.md

@@ -32,7 +32,9 @@ Can you figure out how it does it?
 This program takes no arguments. It emits the base 8 representation
 of prime palindromes (palindromic in base 8, of course).
 
-`^_^`
+```
+^_^
+```
 
 
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