readme: Update Ray job submission example

Commit 0975fb2 changes the CLI groups `finetune` and `evaluate`, but the
Ray job submission example in the README file still uses the deprecated
`run` command.

Update the example to match the new API.

Signed-off-by: Dimitris Poulopoulos <[email protected]>

README.md

@@ -85,7 +85,7 @@ runtime_env = {
 
 # Assuming 'config.yaml' is present in the working directory
 client.submit_job(
-    entrypoint="lm_buddy run <job-name> --config config.yaml", 
+    entrypoint="lm_buddy finetune <job-name> --config config.yaml", 
     runtime_env=runtime_env,
     entrypoint_num_gpus=1
 )