Add citation to readme.

CITATION.cff

@@ -29,6 +29,9 @@ identifiers:
   - description: "This is the archived snapshot of version 0.5 of dcor"
     type: doi
     value: 10.5281/zenodo.3996697
+  - description: "This is the archived snapshot of version 0.6 of dcor"
+    type: doi
+    value: 10.5281/zenodo.7484447
 preferred-citation:
   type: article
   title: "dcor: Distance correlation and energy statistics in Python"

README.rst

@@ -56,6 +56,32 @@ The package dcor depends on the following libraries:
 - scipy
 - joblib
 
+Citing dcor
+===========
+Please, if you find this software useful in your work, reference it citing the following paper:
+
+@article{ramos-carreno+torrecilla_2023_dcor,
+  author = {Ramos-Carreño, Carlos and Torrecilla, José L.},
+  doi = {10.1016/j.softx.2023.101326},
+  journal = {SoftwareX},
+  month = {2},
+  title = {{dcor: Distance correlation and energy statistics in Python}},
+  url = {https://www.sciencedirect.com/science/article/pii/S2352711023000225},
+  volume = {22},
+  year = {2023},
+}
+
+You can additionally cite the software repository itself using:
+
+@misc{ramos-carreno_2022_dcor,
+  author = {Ramos-Carreño, Carlos},
+  doi = {10.5281/zenodo.3468124},
+  month = {3},
+  title = {dcor: distance correlation and energy statistics in Python},
+  url = {https://github.com/vnmabus/dcor},
+  year = {2022}
+}
+
 Documentation
 =============
 The documentation can be found in https://dcor.readthedocs.io/en/latest/?badge=latest