Building docs for InnerEye-DeepLearning

1. First, make sure you have set up your conda environment as described in the Quick Setup Guide.
2. Run make html from the docs folder. This will create html files under docs/build/html.
3. From the docs/build/html folder, run python -m http.server 8080 to host the docs locally.
4. From your browser, navigate to http://localhost:8080 to view the documentation.