docs: fix env example in readme (#141)

Author: aslafy-z

README.md

@@ -277,7 +277,7 @@ endpoint: "{{outputs.cluster_composition.output.value.redis_endpoint}}"
 
 ### Merge with env variables
 ```yaml
-kubeconfig_location: {{env(KUBECONFIG)}}
+kubeconfig_location: "{{env(KUBECONFIG)}}"
 ```
 
 
@@ -387,4 +387,4 @@ config_processor.process(path=path, filters=filters, exclude_keys=exclude_keys,
                          output_format=output_format, print_data=True,
                          type_strategies= [(list, [strategy_merge_override,'append']), (dict, ["merge"])] ))
 
-```
+```