[example] Add fastfold tutorial (#2528)

* add fastfold example

* pre-commit polish

* pre-commit polish readme and add empty test ci

* Add test_ci and reduce the default sequence length

examples/tutorial/fastfold/README.md

@@ -0,0 +1,47 @@
+# FastFold Inference
+
+## Table of contents
+
+- [Overview](#📚-overview)
+- [Quick Start](#🚀-quick-start)
+- [Dive into FastFold](#🔍-dive-into-fastfold)
+
+## 📚 Overview
+
+This example lets you to quickly try out the inference of FastFold.
+
+**NOTE: We use random data and random parameters in this example.**
+
+
+## 🚀 Quick Start
+
+1. Install FastFold
+
+We highly recommend installing an Anaconda or Miniconda environment and install PyTorch with conda.
+
+```
+git clone https://github.com/hpcaitech/FastFold
+cd FastFold
+conda env create --name=fastfold -f environment.yml
+conda activate fastfold
+python setup.py install
+```
+
+2. Run the inference scripts.
+
+```bash
+python inference.py --gpus=1 --n_res=256 --chunk_size=None --inplace
+```
++ `gpus` means the DAP size
++ `n_res` means the length of residue sequence
++ `chunk_size` introduces a memory-saving technology at the cost of speed, None means not using, 16 may be a good trade off for long sequences.
++ `inplace` introduces another memory-saving technology with zero cost, drop `--inplace` if you do not want it.
+
+## 🔍 Dive into FastFold
+
+There are another features of FastFold, such as:
++ more excellent kernel based on triton
++ much faster data processing based on ray
++ training supported
+
+More detailed information can be seen [here](https://github.com/hpcaitech/FastFold/).