Adding PHP highlighting to code examples in README.md

Author: david-binda

README.md

@@ -24,14 +24,14 @@ In order to be able to properly use this plugin you'll have to add some constant
 
 If default values for running PHPCS command does not match your environment (see https://github.com/Automattic/phpcs-diff/blob/master/class-phpcs-diff.php#L5 ), you need to override those via constants located in wp-config.php of your WordPress installation:
 
-```
+```php
 define( 'PHPCS_DIFF_COMMAND', 'phpcs' );
 define( 'PHPCS_DIFF_STANDARDS', 'path/to/phpcs/standards' );
 ```
 
 Alternatively, if you are using the PHPCS_Diff class outside of this plugin, you can pass those in the `(array) $options` param to class' constructor from the WP CLI command - https://github.com/Automattic/phpcs-diff/blob/master/wp-cli-command.php#L64
 
-```
+```php
 new PHPCS_Diff( new PHPCS_Diff_SVN( $repo ), array( 'phpcs_command' => 'my_phpcs_command', 'standards_location' => 'my/standards/location' ) );
 ```
 
@@ -41,30 +41,30 @@ new PHPCS_Diff( new PHPCS_Diff_SVN( $repo ), array( 'phpcs_command' => 'my_phpcs
 
 You need to provide the plugin SVN credentials. This can be done using following constants put into wp-config.php file of your WordPress installation:
 
-```
+```php
 define( 'PHPCS_DIFF_SVN_USERNAME', 'my_svn_username' );
 define( 'PHPCS_DIFF_SVN_PASSWORD', 'my_svn_password' );
 ```
 
 Alternatively, if you are using the `PHPCS_Diff` and `PHPCS_Diff_SVN` classes outside of this plugin, you can pass those via the `(array) $options` param to class' constructor from the WP CLI command - https://github.com/Automattic/phpcs-diff/blob/master/wp-cli-command.php#L64
 
-```
+```php
 new PHPCS_Diff_SVN( $repo, array( 'svn_username' => 'my_username', 'svn_password' => 'my_password' ) );
 ```
 
 ### Repository
 
 You'll have to either register your repository in the `PHPCS_Diff_SVN`'s constructor ( [example](https://github.com/Automattic/phpcs-diff/blob/master/class-phpcs-diff-svn.php#L25,L27) ) or pass your own repository to the constructor via `(array) $options` param from the WP CLI command - https://github.com/Automattic/phpcs-diff/blob/master/wp-cli-command.php#L64
 
-```
+```php
 new PHPCS_Diff_SVN( $repo, array( 'repo_url' => 'https://plugins.svn.wordpress.org/hello-dolly' ) );
 ```
 
 # Running the WP CLI command
 
 Example command run:
 
-```
+```php
 wp phpcs-diff --repo="hello-dolly" --start_revision=99998 --end_revision=100000
 ```