=== Use External YAML for values

It is a common pattern to use a main template file that depends on additional values provided in an external file, yamlfu provides this capability with the `-x` command line option.

e.g
```sh
yamlfu main.yaml -x services/nginx.yaml
```

[cols="1a,1a", options="header"]
.Extra YAML example
|===
|YAMLFu|YAML|
.main.yaml
[source, yaml]
....
include::../yamlfu/tests/files/_extra_yaml.yaml[]
....
.services/nginx.yaml
[source, yaml]
....
include::../yamlfu/tests/files/services/nginx.yaml[]
....
|
.yamlfu main.yaml -x ervices/nginx.yaml
[source, yaml]
....
include::../yamlfu/tests/files/_extra_yaml_result.yaml[]
....
|===
