Add doi information

CITATION.cff

@@ -8,6 +8,10 @@ authors:
     email: "opapst@ikp.tu-darmstadt.de"
     affiliation: "Technische Universität Darmstadt, Department of Physics, Institut für Kernphysik"
     orcid: "https://orcid.org/0000-0002-1037-4183"
+identifiers:
+  - type: doi
+    value: 10.5281/zenodo.11147261
+    description: The concept DOI of the work
 repository-code: "https://github.com/op3/boris"
 abstract: "boris is a modern MCMC-based code that can be used to reconstruct incident nuclear spectra via forward fitting"
 license: GPL-3.0-or-later

README.md

@@ -1,5 +1,6 @@
 # boris
 
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.11147261.svg)](https://doi.org/10.5281/zenodo.11147261)
 [![Test Status](https://img.shields.io/github/actions/workflow/status/op3/boris/run-tests.yml?branch=master&label=tests)](https://github.com/op3/boris/actions/workflows/run-tests.yml)
 [![Code Style](https://img.shields.io/github/actions/workflow/status/op3/boris/check-code-formatting.yml?branch=master&label=style)](https://github.com/op3/boris/actions/workflows/check-code-formatting.yml)
 [![codecov](https://codecov.io/gh/op3/boris/branch/master/graph/badge.svg)](https://codecov.io/gh/op3/boris)