Link to ESLint instead of JSHint, because more popular+versatile, is used by default for devtools linting (https://wiki.mozilla.org/DevTools/CodingStandards) and also for addons checks (https://wiki.mozilla.org/WebExtensions/Hacking)
Add TypeScript since its source map is supported so people googling for "firefox developer tools typescript source maps" end up here
Why does MDN look different?
MDN is changing to focus just on documenting web technologies. All the same great content is still here; we’re just changing some visual elements and navigation, to help you more quickly find the web technology docs you’re looking for.
But don’t worry, MDN and Mozilla are still together! In fact, we're updating MDN’s look to reflect Mozilla's new logo and colors.