📝 update readme

DeepChem has a number of "soft" requirements. These are packages which are needed for various submodules of DeepChem but not for the package as a whole.

- [BioPython](https://biopython.org/wiki/Documentation)

- [OpenAI Gym](https://gym.openai.com/)

- [MDTraj](http://mdtraj.org/)

- [NetworkX](https://networkx.github.io/documentation/stable/index.html)

- [OpenMM](http://openmm.org/)

- [PDBFixer](https://github.com/pandegroup/pdbfixer)

- [Pillow](https://pypi.org/project/Pillow/)

- [pyGPGO](https://pygpgo.readthedocs.io/en/latest/)

- [PyTorch](https://pytorch.org/)

- [RDKit](http://www.rdkit.org/docs/Install.html)

- [simdna](https://github.com/kundajelab/simdna)

- [XGBoost](https://xgboost.readthedocs.io/en/latest/)

`deepchem<2.4.0`

```bash

pip install tensorflow==1.15

pip install tensorflow==1.14

conda install -c rdkit -c conda-forge -c omnia deepchem==2.3.0

```

If you want GPU support:

```bash

pip install tensorflow-gpu==1.15

pip install tensorflow-gpu==1.14

conda install -c rdkit -c conda-forge -c omnia deepchem==2.3.0

```

`deepchem<2.4.0`

```bash

pip install pandas pillow scikit-learn==0.22 tensorflow==1.15 deepchem==2.2.1.dev54

pip install pandas pillow scikit-learn==0.22 tensorflow==1.14 deepchem==2.2.1.dev54

```

If you want GPU support:

```bash

pip install pandas pillow scikit-learn==0.22 tensorflow-gpu==1.15 deepchem==2.2.1.dev54

pip install pandas pillow scikit-learn==0.22 tensorflow-gpu==1.14 deepchem==2.2.1.dev54

```

### Install from source

```

conda activate deepchem

python setup.py install                                # Manual install

python setup.py install

```

Check [this link](https://conda.io/projects/conda/en/latest/user-guide/install/index.html) for more information about the installation of conda environments.