Add doi badge, CITATION.cff

CITATION.cff

@@ -0,0 +1,18 @@
+cff-version: 1.2.0
+title: "AngularCorrelation.jl"
+message: "If you use this software, please cite it using the metadata from this file."
+type: software
+authors:
+  - given-names: "Oliver"
+    family-names: "Papst"
+    email: "[email protected]"
+    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.11145369
+    description: The concept DOI of the work
+repository-code: "https://github.com/op3/AngularCorrelation.jl"
+abstract: "A package to calculate angular distributions and correlations for γ cascades"
+license: GPL-3.0-or-later
+date-released: 2024-05-08

README.md

@@ -1,5 +1,6 @@
 # AngularCorrelation.jl
 
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.11145369.svg)](https://doi.org/10.5281/zenodo.11145369)
 [![GitHub CI](https://github.com/op3/AngularCorrelation.jl/workflows/CI/badge.svg)](https://github.com/op3/AngularCorrelation.jl/actions)
 [![License: Gnu GPL v3+](https://img.shields.io/badge/License-GPL%20v3+-blue.svg)](LICENSE)