Updates readme

README.md

@@ -1,6 +1,6 @@
 Documentation
 =============
-This is the documentation for the [MATLAB](https://github.com/RascalSoftware/RAT) and [Python](https://github.com/RascalSoftware/python-RAT) version of the RAT project. 
+This is the documentation for the [MATLAB](https://github.com/RascalSoftware/RAT) and [Python](https://github.com/RascalSoftware/python-RAT) versions of the RAT project. 
 
 Build docs
 ----------
@@ -12,6 +12,20 @@ in the requirements.txt.
     conda activate RAT
     pip install -r requirements.txt
 
-In the terminal with access to the python executable 
+Download the appropriate version of RAT from the GitHub [release](https://github.com/RascalSoftware/RAT/releases) page, and unzip the contents into a folder called API (This folder should be in the root directory). For example on a Linux machine, the nightly can be downloaded as shown 
+
+    wget https://github.com/RascalSoftware/RAT/releases/download/nightly/Linux.zip
+    unzip Linux.zip -d API/
+
+
+To build the HTML docs, type the following into a terminal with access to the Python executable:  
 
     make html
+
+[`matlabengine`](https://pypi.org/project/matlabengine/) is required to generate MATLAB code snippet outputs. If `matlabengine` is not installed, the outputs will be omitted and the following warning will be printed in the terminal:
+
+    UserWarning: Could not create output as MATLAB engine was not available
+
+If the MATLAB code outputs are needed, install the appropriate `matlabengine` for your installed MATLAB
+
+    pip install matlabengine

source/conf.py

@@ -5,7 +5,6 @@
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-import re
 import os
 import sys
 import datetime
@@ -18,6 +17,9 @@
 current_dir = os.path.dirname(os.path.abspath(__file__))
 # matlab_src_dir is required for sphinxcontrib-matlabdomain
 matlab_src_dir = os.path.abspath(os.path.join(current_dir, '..', 'API'))
+if not os.path.isdir(matlab_src_dir) or not os.path.isfile(os.path.join(matlab_src_dir, 'version.txt')):
+    raise FileNotFoundError(f'A RAT MATLAB release could not be found in {matlab_src_dir}. ' 
+                            'Please download and extract the RAT release to the API folder.')
 sys.path.insert(0, matlab_src_dir)
 
 import RATapi