Fix indentation in README.md

Cleaning up indentation.

Author: kubealex

README.md

@@ -57,7 +57,7 @@ sudo podman run \
     -v /var/lib/containers/storage:/var/lib/containers/storage \
     quay.io/centos-bootc/bootc-image-builder:latest \
     --type qcow2 \
-	--use-librepo=True \
+    --use-librepo=True \
     quay.io/centos-bootc/centos-bootc:stream9
 ```