add "Citing" section

Author: kevinsung

Diff for: CITATION.bib

@@ -0,0 +1,10 @@
+@software{the_qiskit_research_developers_and_contr_2023_7776174,
+  author    = {The Qiskit Research developers and contributors},
+  title     = {Qiskit Research},
+  month     = mar,
+  year      = 2023,
+  publisher = {Zenodo},
+  version   = {v0.0.2},
+  doi       = {10.5281/zenodo.7776174},
+  url       = {https://doi.org/10.5281/zenodo.7776174}
+}

Diff for: README.md

@@ -21,3 +21,9 @@ Documentation is located [here](https://qiskit-research.github.io/qiskit-researc
 ## Contributing
 
 For information on how to contribute to this project, please take a look at our [contribution guidelines](CONTRIBUTING.md).
+
+## Citing
+
+[![DOI](https://zenodo.org/badge/498756635.svg)](https://zenodo.org/badge/latestdoi/498756635)
+
+Qiskit Research is automatically uploaded to Zenodo with every release. Click the badge above to see all citation formats for all versions, or just use [this BibTeX file](CITATION.bib).