not throw error when remove files not exists
diff --git a/bin/release.sh b/bin/release.sh
index 14ac86f..c3c7eb4 100644
--- a/bin/release.sh
+++ b/bin/release.sh
@@ -82,7 +82,7 @@
 fi
 cd ${handbookProjectDir}
 npm run build:${envType}
-rm -r ${websiteTargetDir}/handbook
+rm -rf ${websiteTargetDir}/handbook
 cp -R ${handbookProjectDir}/dist ${websiteTargetDir}/handbook
 echo "Build handbook done."