Add README draft

README.md

-# openfold
+# OpenFold
+
+A faithful PyTorch reproduction of DeepMind's 
+[AlphaFold 2](https://github.com/deepmind/alphafold).
+
+## Installation
+
+1. Install Python 3.9 and install dependencies.
+
+```bash
+pip3 install -r requirements.txt
+```
+
+2. Install third-party dependencies.
+
+```bash
+scripts/install_third_party_dependencies.py
+```
+
+## Features
+
+OpenFold fully reproduces AlphaFold's inference and data processing pipelines, 
+but is written entirely in PyTorch rather than JAX/TensorFlow. It is capable of 
+importing AlphaFold's original pretrained weights.
+
+Future versions will support multi-GPU training with 
+[DeepSpeed](https://github.com/microsoft/DeepSpeed).