Fix caps and highlight .shellcheckrc sample

Directive.md

@@ -1,4 +1,4 @@
-# ShellCheck Directives
+# ShellCheck directives
 
 Shellcheck directives allow you to control how `shellcheck` works, and take the form of comments in files:
 
@@ -11,8 +11,8 @@ hexToAscii() {
 
 or entries in a `.shellcheckrc` in the project root or user's home directory:
 
-```none
-$ cat ~/.shellcheckrc
+```shellcheckrc
+# ~/.shellcheckrc
 
 # Don't suggest [ -n "$VAR" ] over [ ! -z "$VAR" ] 
 disable=SC2236
@@ -23,8 +23,8 @@ enable=require-variable-braces
 
 ## Supported directives
 
-### disable
-Prevent shellcheck from processing one or more warnings:
+### `disable`
+Prevent ShellCheck from processing one or more warnings:
 
 ```sh
 # shellcheck disable=code[,code...]
@@ -39,7 +39,7 @@ A range of errors can also be specified, handy when disabling things for the ent
 
 An alias `all` is available instead of specifying 0-9999 to disable all checks.
 
-### enable
+### `enable`
 
 Enables an [[optional]] check (since 0.7.0).
 
@@ -51,7 +51,7 @@ echo "Hello $USER"  # Will suggest ${USER}
 
 To see a list of optional checks with examples, run `shellcheck --list-optional`. See [[here|optional]] for more information.
 
-### external-sources
+### `external-sources`
 
 Set whether or not to follow arbitrary file paths in `source` statements (since 0.8.0).
 
@@ -59,7 +59,7 @@ Use `external-sources=true` in `.shellcheckrc` to let shellcheck access arbitrar
 
 Individual script files can disable but not enable this option.
 
-### source
+### `source`
 Tell ShellCheck where to find a sourced file (since 0.4.0):
 
 ```sh
@@ -67,9 +67,9 @@ Tell ShellCheck where to find a sourced file (since 0.4.0):
 . "$(locate_config)"
 ```
 
-### source-path
+### `source-path`
 
-Give ShellCheck a path in which to search for sourced file (since 0.7.0).
+Give ShellCheck a path in which to search for sourced files (since 0.7.0).
 
 ```sh
 # The script will now look for src/examples/mylib.sh
@@ -89,7 +89,7 @@ here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 . "$here/utils.sh"
 ```
 
-### shell
+### `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)):
 
@@ -151,4 +151,4 @@ The comment can also be added at the end of the directive line. This is the reco
 ```sh
 # shellcheck disable=SC1234 # this is intentional
 statement_where_warning_should_be_disabled
-```
+```