Update README.md to better show the need for creating config.yml

cd nested

```

#### modify respective paths in 'config_template.yml' save as 'config.yml' and call:

#### modify respective paths in 'config_template.yml':

```

cp config_template.yml config.yml

vi config.yml

```

Note: we're looking into ways to automate this step

#### after 'config.yml' is created call:

```

sudo bash ./setup.sh