Add citation file (#11)

* add citation.cff
* cite datacite's lupo correctly

CITATION.cff

@@ -0,0 +1,32 @@
+cff-version: 1.2.0
+message: "If you use this software in your work, please cite it using the following metadata."
+title: "Project-TAPIR: pidgraph-notebooks"
+abstract: "A collection of Jupyter notebooks with examples of querying different PID providers like ORCID, ROR, Crossref and PID graphs like the FREYA PID Graph and OpenAlex for connected objects."
+type: software
+authors:
+  - given-names: "Sandra"
+    family-names: "Mierz"
+    email: "[email protected]"
+    affiliation: "TIB"
+    orcid: "https://orcid.org/0000-0002-8913-9011"
+repository-code: "https://github.com/Project-TAPIR/pidgraph-notebooks"
+license: "BSD-3-Clause"
+keywords:
+  - "FREYA PID Graph"
+  - "ORCID"
+  - "ROR"
+  - "DOI"
+  - "Datacite"
+  - "Crossref"
+  - "OpenAlex"
+references:
+  - authors:
+      - family-names: "Fenner"
+        given-names: "Martin"
+      - family-names: "Garza"
+        given-names: "Kristian"
+    doi: "10.5438/8gb0-v673"
+    repository-code: "https://github.com/datacite/lupo"
+    title: "DataCite Application API"
+    type: software
+    version: "4.5.4"

organization-people/orcid_get_people_by_organization.ipynb

@@ -11,7 +11,7 @@
     "This notebook queries the [ORCID API](https://api.orcid.org/v3.0/) for all [people affiliated with an organization](https://info.orcid.org/faq/how-do-i-find-orcid-record-holders-at-my-institution/) and additionally narrows down the affiliation to people **currently employed** by the organization. From the resulting list of people we output the ORCID iDs.\n",
     "\n",
     "*Disclosure:\n",
-    "The process of querying the ROR API for additional identifiers and using them to query the ORCID API for affiliated people is the same as implemented by the [FREYA PID Graph](https://blog.datacite.org/powering-the-pid-graph/) and can be found in the GitHub repo https://github.com/datacite/lupo.*"
+    "The process of querying the ROR API for additional identifiers and using them to query the ORCID API for affiliated people is the same as used by the [FREYA PID Graph](https://blog.datacite.org/powering-the-pid-graph/) and is implemented in [DataCite Application API](https://doi.org/10.5438/8gb0-v673).*"
    ]
   },
   {
@@ -650,4 +650,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 1
-}
+}