Update license metadata to link to actual `creativeml-openrail-m` license (#4)

- Update license metadata to link to actual `creativeml-openrail-m` license (f939774704c81036fb74a79b7476565ade0b15f0)

README.md

@@ -1,5 +1,5 @@
 ---
-license: other
+license: creativeml-openrail-m
 tags:
 - stable-diffusion
 - text-to-image