Fix variables-file example
@@ -139,7 +139,7 @@ $ hurl --variable host=example.net --variable id=1234 test.hurl
We can also define all injected variables in a file:
```shell
-$ hurl --variables-files vars.env test.hurl
+$ hurl --variables-file vars.env test.hurl
```
where `vars.env` is
