DOC: Added citation.cff

CITATION.cff

+cff-version: 1.2.0
+message: "If you use this software, please cite it as below."
+authors:
+  - family-names: Fitschen
+    given-names: Timm
+    orcid: https://orcid.org/0000-0002-4022-432X
+  - family-names: Schlemmer
+    given-names: Alexander
+    orcid: https://orcid.org/0000-0003-4124-9649
+  - family-names: Hornung
+    given-names: Daniel
+    orcid: https://orcid.org/0000-0002-7846-6375
+  - family-names: tom Wörden
+    given-names: Henrik
+    orcid: https://orcid.org/0000-0002-5549-578X
+  - family-names: Parlitz
+    given-names: Ulrich
+    orcid: https://orcid.org/0000-0003-3058-1435
+  - family-names: Luther
+    given-names: Stefan
+    orcid: https://orcid.org/0000-0001-7214-8125
+title: CaosDB - Advanced User Tools
+version: 0.6.0
+doi: 10.3390/data4020083
+date-released: 2022-10-11
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