update README about profile learner

Signed-off-by: Chao Chen <[email protected]>

README.md

@@ -103,11 +103,7 @@ This will bring up 3 etcd members `infra1`, `infra2` and `infra3` and optionally
 
 Every cluster member and proxy accepts key value reads and key value writes.
 
-Follow the steps in [Procfile.learner](./Procfile.learner) to add a learner node to the cluster. Start the learner node with:
-
-```bash
-goreman -f ./Procfile.learner start
-```
+Follow the comments in [Procfile script](./Procfile) to add a learner node to the cluster.
 
 ### Install etcd client v3