Added @types/jest in installtion commands. (#78090)
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### What?
Updated documentation and installation instructions to include
`@types/jest`.
### Why?
When setting up Jest in a TypeScript project, omitting `@types/jest`
causes TypeScript to fall back to `node:test`, leading to incorrect
module resolution and runtime errors. Including `@types/jest` resolves
this and ensures a smooth development experience.
### How?
Added `@types/jest` to the recommended install commands wherever
applicable, ensuring consistent and error-free setup for users following
the docs.
Closes `NEXT-`
Fixes `#`
