Docs: examples with arrow functions in no-return-assign (fixes #13135)

[anikethsaha]

Prerequisites checklist

• I have read the contributing guidelines.
• The team has reached consensus on the changes proposed in this pull request. If not, I understand that the evaluation process will begin with this pull request and won't be merged until the team has reached consensus.

What is the purpose of this pull request? (put an "X" next to an item)

[X] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)

Added incorrect and correct example using arrow function in docs to represent the parenthesis position.

Is there anything you'd like reviewers to focus on?

fixes #13135

[mdjermanovic]

Thanks for the PR!

Can you please also add an example with a nested assignment in return statement? It could be something like:

function doSomething() {
    return foo = bar && foo > 0;
}

and its correct version:

function doSomething() {
    return (foo = bar) && foo > 0;
}

[mdjermanovic]

LGTM, thanks!

[kaicataldo]

Thanks for doing this! Clearer docs and increased test coverage are always welcome! 🎉