Fix default output to YAML when used interactively

Author: Steve Lee (POWERSHELL HE/HIM) (from Dev Box)

dsc/src/resource_command.rs

@@ -55,6 +55,7 @@ pub fn get(dsc: &DscManager, resource_type: &str, input: &str, format: Option<&G
             let format = match format {
                 Some(&GetOutputFormat::PrettyJson) => Some(&OutputFormat::PrettyJson),
                 Some(&GetOutputFormat::Yaml) => Some(&OutputFormat::Yaml),
+                None => None,
                 _ => Some(&OutputFormat::Json),
             };
             write_object(&json, format, false);