Update version and improve config validation

src/ConfigLib/Configuration.php

@@ -161,9 +161,7 @@
          */
         private static function validateKey(string $input): bool
         {
-            $pattern = '/^([a-zA-Z0-9]+\.?)+$/';
-
-            if (preg_match($pattern, $input))
+            if (preg_match('/^([a-zA-Z0-9_]+\.?)+$/', $input))
             {
                 return true;
             }