docs: update nextjs quickstart

[christiannwamba]

Related Issue or Design Document

Checklist

• I have read the contributing guidelines and signed the CLA.
• I have referenced an issue containing the design document if my change introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security vulnerability.
  If this pull request addresses a security vulnerability,
  I confirm that I got approval (please contact [email protected]) from the maintainers to push the changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added the necessary documentation within the code base (if appropriate).

Further comments

[aeneasr]

You can re-trigger the CI by clicking on the failing task. In cases like this where set up fails on install, it's probably some flake issue. I did it for you in this case

[vinckr]

missing the "Make authenticated requests to your API" part in the text - its there in the code examples we just need to assume the user is starting from scratch and also add it to the text!

[vinckr]

besides the new next.js quickstart I also went over the structure of the other quickstarts to make sure they all have the same order and structure. this is now more or less the case, some (e.g. react native) are still very different due to the nature of the quickstart.

fixed

[aeneasr]

epic, thanks!