update readme for output file

README.md

@@ -20,11 +20,11 @@ Needs the citygml4j quality ade plugin from [here](https://transfer.hft-stuttgar
 Once built there is a CityDoctorValidation-\<version\>.zip file in the target folder of the CityDoctorValidation folder in which the CityDoctorValidation jar can be used to start the program.
 
 ```bash
-java -classpath libs/*;plugins/*;CityDoctorValidation-<version>.jar de.hft.stuttgart.citydoctor2.CityDoctorValidation -in <path-to-gml-file>.gml -config <path-to-validation-config>.yml -xmlReport <path-to-xml-output>.xml -pdfReport <path-to-pdf-output>.pdf
+java -classpath libs/*;plugins/*;CityDoctorValidation-<version>.jar de.hft.stuttgart.citydoctor2.CityDoctorValidation -in <path-to-gml-file>.gml -config <path-to-validation-config>.yml -xmlReport <path-to-xml-output>.xml -pdfReport <path-to-pdf-output>.pdf -out <path-to-output-gml>.gml
 ```
 
 Note:
--xmlReport and -pdfReport are optional
+-xmlReport, -pdfReport and -out are optional
 
 
 ## License