You don't need <noscript> anymore.

bookmarkl.ink can be used to share simple javascript gists, executable in the browser and saved as bookmarklets, like a QR code creator, a reader view, or the entirety of DOOM.

Do

When the core functionality of a feature cannot function with only HTML.
When the core functionality of a feature can benefit from some JavaScript. Start with only HTML, then progressively enhance it, so it can still work without Jav...