Come up with new deployment strategy

[evanepio]

Forestry is going to stop deploying on January 1, 2020.

https://forestry.io/docs/sunset/deployments/

We need a new deployment mechanism in place before then.

[evanepio]

This looks promising and "simple" enough:

https://github.com/marketplace/actions/hugo-for-github-organization-pages

Basically, we have a separate repo for Hugo source files. On commit or push to master, it's generated and committed to the GitHub Organization Pages repo and hence deployed.

The unfortunate thing is, we'd need git submodules to make it work. The Hugo source repo would need the public folder to be a module.