MKDocs Instant loading

[derbyshire10]

Adds the MKDocs function so that when internal links are clicked the page is loaded without refreshing the page.

https://squidfunk.github.io/mkdocs-material/setup/setting-up-navigation/?h=navigation+instant#instant-loading

[theacodes]

I'd prefer us not to enable this, as instant loading has caused several issues in the past and can break user expectations. The benefit isn't worth the gain, and modern browsers will handle asset cache and page navigation more than well enough.

[derbyshire10]

Ok fair enough, it might be worth considering when instant prefetching becomes available in the community edition.

[theacodes]

Cool, we'll hold off on this for now.