fix: correct opts reg sig push

docs/cli/reference/registry.mdx

@@ -68,7 +68,7 @@ scale registry function delete [<org>/<name>:<tag>]
 To push a signature to the registry, use the `push` command:
 
 ```bash
-scale registry signature push [<name>:<tag> | [<org>/<name>:<tag>]
+scale registry signature push [<org>/<name>:<tag>]
 ```
 
 The signature must be built and available locally in the signature cache to be pushed to the registry.