Add CITATION (#821)

Summary:
Add citation file and update readme to include our bibtex citation for the arXiv paper.

Pull Request resolved: flashlight/flashlight#821

Reviewed By: benoitsteiner

Differential Revision: D34077270

Pulled By: jacobkahn

fbshipit-source-id: ce65f06bdc8758bdf1f2e6f4acab32fe35754d6f

CITATION

@@ -0,0 +1,8 @@
+@misc{kahn2022flashlight,
+      title={Flashlight: Enabling Innovation in Tools for Machine Learning},
+      author={Jacob Kahn and Vineel Pratap and Tatiana Likhomanenko and Qiantong Xu and Awni Hannun and Jeff Cai and Paden Tomasello and Ann Lee and Edouard Grave and Gilad Avidov and Benoit Steiner and Vitaliy Liptchinsky and Gabriel Synnaeve and Ronan Collobert},
+      year={2022},
+      eprint={2201.12465},
+      archivePrefix={arXiv},
+      primaryClass={cs.LG}
+}

README.md

@@ -5,6 +5,7 @@
 [**Quickstart**](#quickstart)
 | [**Installation**](#building-and-installing)
 | [**Documentation**](https://fl.readthedocs.io/en/latest/)
+| [**Citing**](#citing)
 
 [![CircleCI](https://circleci.com/gh/flashlight/flashlight.svg?style=shield)](https://app.circleci.com/pipelines/github/flashlight/flashlight)
 [![Documentation Status](https://img.shields.io/readthedocs/fl.svg)](https://fl.readthedocs.io/en/latest/)
@@ -562,5 +563,18 @@ Flashlight is being very actively developed. See
 Some of Flashlight's code is derived from
 [arrayfire-ml](https://github.com/arrayfire/arrayfire-ml/).
 
+## Citing
+You can cite [Flashlight](https://arxiv.org/abs/2201.12465) using:
+```
+@misc{kahn2022flashlight,
+      title={Flashlight: Enabling Innovation in Tools for Machine Learning},
+      author={Jacob Kahn and Vineel Pratap and Tatiana Likhomanenko and Qiantong Xu and Awni Hannun and Jeff Cai and Paden Tomasello and Ann Lee and Edouard Grave and Gilad Avidov and Benoit Steiner and Vitaliy Liptchinsky and Gabriel Synnaeve and Ronan Collobert},
+      year={2022},
+      eprint={2201.12465},
+      archivePrefix={arXiv},
+      primaryClass={cs.LG}
+}
+```
+
 ## License
 Flashlight is under an MIT license. See [LICENSE](LICENSE) for more information.