update readme and citation file to reference paper

CITATION.bib

@@ -1,8 +1,13 @@
-@misc{qiskit_dynamics_2021,
-  author = {Egger, Daniel J. and Hincks, Ian and Landa, Haggai and Malekakhlagh, Moein and Parr, Avery and Puzzuoli, Daniel and Rosand, Benjamin and Rupesh, R. K. and Treinish, Matthew and Ueda, Kento and Wood, Christopher J.},
-  title = {Qiskit Dynamics},
-  year = {2021},
-  publisher = {GitHub},
-  journal = {GitHub repository},
-  url = {https://github.com/Qiskit-Extensions/qiskit-dynamics}
-}
+@article{qiskit_dynamics_2023,
+	title = {Qiskit {Dynamics}: {A} {Python} package for simulating the time dynamics of quantum systems},
+	volume = {8},
+	issn = {2475-9066},
+	url = {https://joss.theoj.org/papers/10.21105/joss.05853},
+	doi = {10.21105/joss.05853},
+	language = {en},
+	number = {90},
+	journal = {Journal of Open Source Software},
+	author = {Puzzuoli, Daniel and Wood, Christopher J. and Egger, Daniel J. and Rosand, Benjamin and Ueda, Kento},
+	year = {2023},
+	pages = {5853}
+}

README.md

@@ -1,6 +1,7 @@
 # Qiskit Dynamics
 
 [![License](https://img.shields.io/github/license/Qiskit/qiskit-dynamics.svg?style=popout-square)](https://opensource.org/licenses/Apache-2.0)
+[![DOI](https://joss.theoj.org/papers/10.21105/joss.05853/status.svg)](https://doi.org/10.21105/joss.05853)
 
 **This repo is still in the early stages of development, there will be breaking API changes**
 
@@ -60,7 +61,8 @@ questions. For questions that are more suited for a forum we use the Qiskit tag
 
 Qiskit Dynamics is the work of 
 [many people](https://github.com/Qiskit-Extensions/qiskit-dynamics/graphs/contributors) who
-contribute to the project at different levels. If you use Qiskit, please cite as per the included 
+contribute to the project at different levels. If you use Qiskit Dynamics, please cite our paper as
+per the included 
 [BibTeX file](https://github.com/Qiskit-Extensions/qiskit-dynamics/blob/main/CITATION.bib).
 
 ## License