Docs site getting really hard to run locally

[GuySartorelli]

Every time I want to run the docs site locally to test some change it gets harder to get it running, and I have to do all sorts of whacky temporary code changes.
Most recently this includes updating a bunch of packages locally in order to get it running.

We really need to update the JS on this thing to make it easier to run locally, especially since the dot org refresh seems like it's not happening any time soon.

Acceptance criteria

• node version and js deps are updated
• Guy doesn't have to jump through a bunch of hoops to get the docs site running locally
• Docs sites still deploy preview correctly on each PR to this repo
• Docs sites still deploy to prod correctly
• No obvious changes to dev docs nor user help sites (functionality and visually)

[maxime-rainville]

There's many different ways we could meet these ACs. We also have a potential project to fold the doc back into a new DotOrg site. Before spending too much time optimising or documenting the current approach, maybe we should have a look at alternative approaches.

Validation steps

• Validate what's going with DotOrg
• Identify alternative ways of rendering/building the doc site.