Migrate build and hosting to GitHub

[NickRoach]

At the moment we use Netify to build and host the website. In order to centralise control of the website to eliminate potential dependencies on Michael or other members who might leave, we should:

• Migrate the build to a GitHub action using Michael's blog deployment as a template.

• Host the website using GitHub pages.

• Once it is hosted under GitHub pages, point the DNS servers to the GitHub hosted site instead of the Netify hosted site