Merge pull request #18 from PHPCompatibility/feature/readme-update-for-composer-2.2

README: update for Composer 2.2

Author: wimg

README.md

@@ -38,14 +38,13 @@ The minimum _recommended_ version of PHP_CodeSniffer is version 2.6.0.
 
 If you don't have a Composer plugin installed to manage the `installed_paths` setting for PHP_CodeSniffer, run the following from the command-line:
 ```bash
+composer config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
 composer require --dev dealerdirect/phpcodesniffer-composer-installer:"^0.7" phpcompatibility/phpcompatibility-all:"*"
-composer install
 ```
 
 If you already have a Composer PHP_CodeSniffer plugin installed, run:
 ```bash
 composer require --dev phpcompatibility/phpcompatibility-all:"*"
-composer install
 ```
 
 Next, run: