Add citation

README.md

@@ -1,10 +1,25 @@
 # FourierSpaces.jl
 
-Goals
+## Goals
 - [ ] Transformation-based spaces
     - [X] Fourier space
     - [ ] Sine space
     - [ ] Cosine space
     - [ ] Chevyshev transform space??
 - [ ] Separate out FFT library compilation - make CUDA.jl a requires/extension
 - [ ] make it more general so any transform-based PDE solver can use preexisting abstractions
+
+
+
+## Citation
+
+```
+@software{fourierspacesjl,
+  author = {Puri, Vedant},
+  title = {FourierSpaces.jl: Fourier spectral PDE solvers in Julia},
+  year = {2022},
+  publisher = {GitHub},
+  journal = {GitHub repository},
+  howpublished = {\url{https://github.com/CalculustJL/FourierSpaces.jl}}
+}
+```