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.

2019/giles/README.md

@@ -67,7 +67,7 @@ Interesting fact: The size of the program from `./iocccsize -i` is 2019.
 ./prog input [output [size [dry [wet [damping]]]]]
 prog.exe input [output [size [dry [wet [damping]]]]]
 ```
-\
+
 * `input`: The path to the input file. Required.
 * `output`: The path to the output file. Optional, defaults to `out.wav`.
 * `size`: The perceived size of the room, i.e. the approximate amount of time