chore: codeinwp/phpcs-ruleset composer dependency added

Author: Mustafa Şükrü Kapusuz

composer.json

@@ -17,6 +17,9 @@
         "platform-check": false,
         "platform": {
             "php": "7.0"
+        },
+        "allow-plugins": {
+            "dealerdirect/phpcodesniffer-composer-installer": true
         }
     },
     "extra": {
@@ -32,6 +35,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^6.5",
-        "yoast/phpunit-polyfills": "^1.0"
+        "yoast/phpunit-polyfills": "^1.0",
+        "codeinwp/phpcs-ruleset": "dev-main"
     }
 }