Update README.md

Author: nielshulstaert

README.md

@@ -20,6 +20,7 @@ For running on Windows, omit `mono`. The optional parameters only work in the -o
 ThermoRawFileParser.exe --help
  usage is (use -option=value for the optional arguments):
   -h, --help                 Prints out the options.
+      --version              Prints out the library version.
   -i, --input=VALUE          The raw file input.
   -o, --output=VALUE         The output directory. Specify this or an output
                                file.