Add citation (#66)

README.md

@@ -1,5 +1,23 @@
 # ExaWind Simulation Driver
+[![journal article](https://img.shields.io/badge/DOI-10.1002/we.2886-blue)](https://doi.org/10.1002/we.2886)
 
 This repository contains a pure C++ driver API for coupling
 [Nalu-Wind](https://github.com/exawind/nalu-wind) and
 [AMR-Wind](https://github.com/exawind/amr-wind) CFD codes.
+
+## Citation
+
+To cite ExaWind or the usage of this driver and to learn more about the methodology, use the following [journal article](https://doi.org/10.1002/we.2886):
+```
+@article{exawind2024,
+    author = {Sharma, Ashesh and Brazell, Michael J. and Vijayakumar, Ganesh and Ananthan, Shreyas and Cheung, Lawrence and deVelder, Nathaniel and {Henry de Frahan}, Marc T. and Matula, Neil and Mullowney, Paul and Rood, Jon and Sakievich, Philip and Almgren, Ann and Crozier, Paul S. and Sprague, Michael},
+    title = {{ExaWind: Open-source CFD for hybrid-RANS/LES geometry-resolved wind turbine simulations in atmospheric flows}},
+    journal = {Wind Energy},
+    volume = {},
+    number = {},
+    pages = {},
+    doi = {10.1002/we.2886},
+    url = {https://doi.org/10.1002/we.2886},
+    eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1002/we.2886}
+}
+```