Added Step to Setup Instructions

Added an instruction step to have git installed, then use git to clone the repository.
For newbies like me who tried just downloading the files manually, and in that case the "Setup Submodules" git command didn't work.

SETUP.md

@@ -1,10 +1,11 @@
 ## Setup
 1. Install anaconda or miniconda
-2. Create environment: `conda create -n ganspace python=3.7`
-3. Activate environment: `conda activate ganspace`
-4. Install dependencies: `conda env update -f environment.yml --prune`
-5. Setup submodules: `git submodule update --init --recursive`
-6. Run command `python -c "import nltk; nltk.download('wordnet')"`
+2. Install git, then clone respository: `git clone https://github.com/harskish/ganspace/`
+3. Create environment: `conda create -n ganspace python=3.7`
+4. Activate environment: `conda activate ganspace`
+5. Install dependencies: `conda env update -f environment.yml --prune`
+6. Setup submodules: `git submodule update --init --recursive`
+7. Run command `python -c "import nltk; nltk.download('wordnet')"`
 
 ### Interactive viewer
 The interactive viewer (<i>interactive.py</i>) has the following dependencies: