docs: fix warning position - move it above parameters (#599)

Author: bshaffer

src/CredentialsLoader.php

@@ -120,19 +120,19 @@ public static function fromWellKnownFile()
     /**
      * Create a new Credentials instance.
      *
+     * **Important**: If you accept a credential configuration (credential JSON/File/Stream) from an
+     * external source for authentication to Google Cloud Platform, you must validate it before
+     * providing it to any Google API or library. Providing an unvalidated credential configuration to
+     * Google APIs can compromise the security of your systems and data. For more information
+     * {@see https://cloud.google.com/docs/authentication/external/externally-sourced-credentials}
+     *
      * @param string|string[] $scope the scope of the access request, expressed
      *        either as an Array or as a space-delimited String.
      * @param array<mixed> $jsonKey the JSON credentials.
      * @param string|string[] $defaultScope The default scope to use if no
      *   user-defined scopes exist, expressed either as an Array or as a
      *   space-delimited string.
      *
-     * **Important**: If you accept a credential configuration (credential JSON/File/Stream) from an
-     * external source for authentication to Google Cloud Platform, you must validate it before
-     * providing it to any Google API or library. Providing an unvalidated credential configuration to
-     * Google APIs can compromise the security of your systems and data. For more information
-     * {@see https://cloud.google.com/docs/authentication/external/externally-sourced-credentials}
-     *
      * @return ServiceAccountCredentials|UserRefreshCredentials|ImpersonatedServiceAccountCredentials|ExternalAccountCredentials
      */
     public static function makeCredentials(