Frontpage Alterations

[RichGriff]

Hey @chrisdburr, I have made the changes you required.

• Scroll down arrow added
• No animations when scrolling back through (note: animation only happens on page load and when items come into view)
• Removed the main.html override as this causes issues for other pages. I managed to remove the class only for the frontpage, so you can still have the full width sections.

Any issues, please let me know.

[chrisdburr]

@RichGriff would you mind redoing this PR into the homepage branch please? We have GitHub Actions set up on the main branch to automatically compile and host the site from the main branch so it is only used for production-ready code. I would need to make some changes to this PR before it was ready to go live (e.g. adding proper images and copy).

https://github.com/alan-turing-institute/turing-commons/tree/homepage