Refine multi line codeblock formating

Some shells set the line background for complete terminal width instead of only the available characters to print

catmd.sh

@@ -190,12 +190,15 @@ parseline() {
       5) ## Multiline code blocks ##
         if [[ "$tocheck" =~ $rex_codeblock ]]; then
           if isfix; then
-            format_suffix="${FO_RESET}"
             unfix
           else
-            format_prefix="${FO_CODEBLOCK}"
             fix
           fi
+          format_prefix="${FO_CODEBLOCK}"
+          format_suffix="${FO_RESET}"
+        elif isfix; then
+            format_prefix="${FO_CODEBLOCK}"
+            format_suffix="${FO_RESET}"
         fi
         fall || break;;
       6) ## Code block started with spaces