Description

❓What: fixed some broken links and added some further details

🧠Why?: spotted by Sarah Culkin that some of the links in the repo were broken

👨‍💻How?: replaced them with new links

Checklist:

Have checked for the following:

[x] The website still builds correctly, and you can view it using mkdocs serve.
[x] There are no new "warnings" from mkdocs
[x] Does your page follow the page template (or here in Markdown)? (need to make a new one specific to NHSE Data Science)
[x] Spelling errors
[x] Consistent capitalization
[x] Consistent numbers
[x] Material features incorrectly implemented: search for code blocks and markers (e.g. !!!).
[x] Code snippets don't work
[x] Images not working
[x] Links not working