This allows a page to be fully static (no runtime JavaScript) on a per-page basis.
The initial implementation does not disable JS in development mode as we need to figure out a way to inject CSS from CSS imports / CSS modules without executing the component JS. This restriction is somewhat similar to https://www.gatsbyjs.org/packages/gatsby-plugin-no-javascript/. All things considered that plugin only has a usage of 600 downloads per week though, hence why I've made this option unstable/experimental initially as I'd like to see adoption patterns for it first.
Having a built-in way to do this makes sense however as the people that do want to adopt this pattern are overriding Next.js internals currently and that'll break between versions.
Related issue: #5054 - Not adding `fixes` right now as this implementation needs more work. If anyone wants to work on this feel free to reach out on https://twitter.com/timneutkens
