attempted markup fix

CHANGES.md

@@ -22,24 +22,30 @@ Known issues:
 
   - Command synopses when argument errors:
 
+    ```
         $ triton create
         triton instance create: error (Usage): incorrect number of args
     >   usage: triton instance create [OPTIONS] IMAGE PACKAGE
+    ```
 
   - Option synopsis with option errors:
 
+    ```
         $ triton image ls --bogus
         triton image ls: error (Option): unknown option: "--bogus"
     >   usage: triton image ls [ --help | -h ] [ --all | -a ] [ -H ] [ -o field1,... ]
     >       [ --long | -l ] [ -s field1,... ] [ --json | -j ] ...
+    ```
 
   - Suggested command name misspellings:
 
+    ```
         $ triton in
         triton: error (UnknownCommand): unknown command: "in"
     >   Did you mean this?
     >       info
     >       inst
+    ```
 
 
 ## 4.12.0