Remove --xpack.endpoint.enabled=true from README.md file (#67053)

- Remove endpoint flag from readme file

Author: paul-tavares

x-pack/plugins/ingest_manager/README.md

@@ -28,7 +28,7 @@ One common development workflow is:
   ```
 - Start Kibana in another shell
   ```
-  yarn start --xpack.ingestManager.enabled=true --no-base-path --xpack.endpoint.enabled=true
+  yarn start --xpack.ingestManager.enabled=true --no-base-path
   ```
 
 This plugin follows the `common`, `server`, `public` structure from the [Architecture Style Guide