feat: EventRecordingExample did not set up input (#878)

It's meant to read in CSV particles using `--input-dir` but didn't set this up in boost po.

Co-authored-by: Andreas Salzburger <Andreas.Salzburger@cern.ch>

Examples/Run/Geant4/HepMC/EventRecordingExample.cpp

@@ -33,6 +33,7 @@ int main(int argc, char* argv[]) {
   ActsExamples::Options::addSequencerOptions(desc);
   ActsExamples::Options::addOutputOptions(
       desc, ActsExamples::OutputFormat::DirectoryOnly);
+  ActsExamples::Options::addInputOptions(desc);
   ActsExamples::Options::addDD4hepOptions(desc);
   ActsExamples::Options::addGeant4Options(desc);
   ActsExamples::Options::addHepMC3WriterOptions(desc);