docs: update migrate-from-redoc-cli.md (#2152)

corrects typo in name of new parameter name

Author: gilzow

docs/@v2/guides/migrate-from-redoc-cli.md

@@ -51,7 +51,7 @@ In both cases, the child options should work as before.
 
 ### Update command-line configuration
 
-Replace your existing `--options.theme.*` settings with a new prefix: `--theme.options.theme.*`.
+Replace your existing `--options.theme.*` settings with a new prefix: `--theme.openapi.theme.*`.
 
 For example if you used `redoc-cli build --options.theme.sidebar.width='300px' openapi.yaml` then the new command would be: