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.

2018/vokes/README.md

@@ -48,36 +48,42 @@ it produces a build order with any dependency cycles gathered.
 
 For example, the following input (provided as `example-1.txt`):
 
-    0 4 8
-    1 0
-    2 1 3
-    3 2
-    4 1
-    5 4 6
-    6 5 2
-    7 3 6 7
+```
+0 4 8
+1 0
+2 1 3
+3 2
+4 1
+5 4 6
+6 5 2
+7 3 6 7
+```
 
 would be interpreted as:
 
-    0 -> 4, 8
-    1 -> 0
-    2 -> 1, 3
-    3 -> 2
-    4 -> 1
-    5 -> 4, 6
-    6 -> 5, 2
-    7 -> 3, 6, 7
+```
+0 -> 4, 8
+1 -> 0
+2 -> 1, 3
+3 -> 2
+4 -> 1
+5 -> 4, 6
+6 -> 5, 2
+7 -> 3, 6, 7
+```
 
 So, node 0 has edges to / depends on nodes 4 and 8, node 1 depends on
 node 0, and so on. Then, it groups the graph's nodes into
 strongly connected components and prints them in reverse-topologically
 sorted order:
 
-    0: 8
-    1: 0 1 4
-    2: 2 3
-    3: 5 6
-    4: 7
+```
+0: 8
+1: 0 1 4
+2: 2 3
+3: 5 6
+4: 7
+```
 
 It uses Tarjan's strongly connected components algorithm for the
 grouping and reverse-topological sorting, along with a bonus hidden
@@ -90,8 +96,10 @@ Limitations".
 
 To build:
 
+```
     ${CC} -o prog prog.c -std=c11 -O3 \
         -Wall -Wextra -pedantic -Wno-missing-prototypes
+```
 
 `-Wno-missing-prototypes` is necessary because there aren't any
 prototypes. (They would put the program well over the size limit.)