Update README.md

Author: scaomath

README.md

@@ -1,13 +1,19 @@
 # Torch CFD
 
-This is a native PyTorch port of Google's Computational Fluid Dynamics package in Jax. The main changes are documented in the `README.md` under the [`torch_cfd` directory](torch_cfd/README.md). The biggest change is many routines that rely on the functional programming of Jax have been rewritten to be a more PyTorch-friendly tensor-in to tensor-out style.
+This is a native PyTorch port of [Google's Computational Fluid Dynamics package in Jax](https://github.com/google/jax-cfd). The main changes are documented in the `README.md` under the [`torch_cfd` directory](torch_cfd/README.md). The biggest change is many routines that rely on the functional programming of Jax have been rewritten to be a more PyTorch-friendly tensor-in to tensor-out style.
 
 ## Installation
 
 ```bash
 pip install torch-cfd
 ```
 
+## Contributions
+PR welcome. Current the port only includes:
+- Pseudospectral methods for vorticity which use anti-aliasing filtering techniques for non-linear terms to maintain stability.
+- Temporal discretization: Currently only RK4 temporal discretization, using explicit time-stepping for advection and either implicit or explicit time-stepping for diffusion.
+- Boundary conditions: only periodic boundary conditions.
+
 ## Examples
 - Demos of different simulation setups:
-  - [2D simulation with a psuedo-spectral solver](example_Kolmogrov2d_rk4_cn_forced_turbulence.ipynb)
+  - [2D simulation with a psuedo-spectral solver](example_Kolmogrov2d_rk4_cn_forced_turbulence.ipynb)