Update license metadata to link to actual `creativeml-openrail-m` license (#19)

- Update license metadata to link to actual `creativeml-openrail-m` license (36c45e9be90658f5bffa92c04d1f90705f7bc061)

README.md

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