Add office hours links to support page

[wwarriner]

As per title.

It may be worth testing out the mkdocs-macros plugin to see if we can avoid defining these in multiple places.

Also consider adding to the footer if sensible.

[wwarriner]

Currently office hours links are at the bottom of this screenshot.

It is definitely worth making them more obvious and accessible.

[wwarriner]

Current best strategy looks like https://github.com/mondeja/mkdocs-include-markdown-plugin

[wwarriner]

We've been working just fine for ages without this. Closing.