Check over project READMEs, in and outside template, and ensure all up-to-date

[James-Osmond]

No description provided.

[James-Osmond]

Note from older ticket (not in this repo):

Sphinx installation and usage will need to be checked as part of this PR, but has already been done in the sphinx-docs branch. All work being done in this repo.

Both READMEs need updating, but the one in the root folder can reference the one in /docs.