fix-index-show-completion, add more completions (#29)

README.md

@@ -145,6 +145,30 @@ make
 sudo make install
 ```
 
+# Development
+
+## To test completion
+
+Add the flag `--generate-shell-completion` to any command, e.g.:
+
+```console
+./esctl role show --generate-shell-completion
+machine_learning_admin
+rollup_admin
+editor
+reporting_user
+snapshot_user
+fcn_admin
+machine_learning_user
+kibana_system
+beats_admin
+kibana_user
+fcns_space
+transport_client
+transform_user
+[..]
+```
+
 # Report bugs
 
 [Please open an issue](https://codeberg.org/scip/esctl/issues). Thanks!