Adds missing year info to some research publications to be displayed …

…correctly on the page.

_research/references.bib

@@ -16,6 +16,7 @@ @InProceedings{Rein2023TSN
   author={Patrick Rein and Tom Beckmann and Eva Krebs and Toni Mattis and Robert Hirschfeld},
   title={Too Simple? Notions of Task Complexity used in Maintenance-based Studies of Programming Tools},
   booktitle={Proceedings of the IEEE/ACM International Conference on Program Comprehension (ICPC) 2023},
+  year={2023},
   pages={254--265},
   doi={10.1109/ICPC58990.2023.00040},
   url={https://doi.org/10.1109/ICPC58990.2023.00040},
@@ -27,6 +28,7 @@ @InProceedings{Geier2023APV
   author={Leonard Geier and Paul Methfessel and Tom Beckmann and Robert Hirschfeld},
   title={Asymmetric Performance in Virtual Reality and Code},
   booktitle={Proceedings of the International Conference on Live Coding (ICLC) 2023},
+  year={2023},
   address={Utrecht, Netherlands},
   pages={7},
   doi={10.5281/zenodo.7843896},