syntax colorization on code blocks

Directive.md

@@ -1,35 +1,43 @@
 Shellcheck directives allow you to control how `shellcheck` works, and take the form of comments in files:
 
-    hexToAscii() {
+```sh
+hexToAscii() {
   # shellcheck disable=SC2059
   printf "\x$1"
-    }
+}
+```
 
 Supported directives are 
 
 ### disable
 Prevent shellcheck from processing one or more warnings:
 
-    # shellcheck disable=code[,code...]
+```sh
-    statement_where_warning_should_be_disabled
+# shellcheck disable=code[,code...]
+statement_where_warning_should_be_disabled
+```
 
 ### source
 Tell ShellCheck where to find a sourced file (since 0.4.0):
 
-    # shellcheck source=src/examples/config.sh
+```sh
-    . "$(locate_config)"
+# shellcheck source=src/examples/config.sh
+. "$(locate_config)"
+```
 
 ### shell
 Specify the shell for a script (similar to the shebang, if you for any reason don't want to add one) (since [0.4.5](https://github.com/koalaman/shellcheck/issues/581#issuecomment-249437837)):
 
-    # shellcheck shell=sh
+```sh
-    echo foo &> bar
+# shellcheck shell=sh
+echo foo &> bar
+```
 
 Directives that replace or are immediately after the shebang apply to the entire script. Otherwise, they are scoped to the command that follows it (including compound commands like function definitions, loops and case statements). A directive may only be applied to a complete command, and can not be used immediately preceding an `else` block or individual `case` branch:
 
-
+```sh
-    # Directive VALID here, applies to whole `case`
+# Directive VALID here, applies to whole `case`
-    case $1 in
+case $1 in
   # Directive INVALID, `-v)` is not a complete command
   -v)
     # Directive VALID here, applies to whole `if`
@@ -42,18 +50,20 @@ Directives that replace or are immediately after the shebang apply to the entire
       v=1
     fi ;;
  esac
-
+```
 
 There is no support for scoping a directive to the first structure of the script. In these cases, use a dummy command `true` or `:` and then add directives, such as
 
-    # This directive applies to the entire script
+```sh
-    # shellcheck disable=2086
+# This directive applies to the entire script
-    true
+# shellcheck disable=2086
+true
 
-    # This directive only applies to this function
+# This directive only applies to this function
-    # shellcheck disable=2043
+# shellcheck disable=2043
-    f() {
+f() {
   ...
-    }
+}
+```
 
 Silencing parser errors is purely cosmetic; any parser error found will still stop ShellCheck at the point of the error.