Docs: Add article about restrict-plus-operands & restrict-template-expressions best practices

[JoshuaKGoldberg]

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Suggested Changes

Forking from @bradzacher's #6110 (comment) (context: adding more allow* options to restrict-plus-operands):

I'm unhappy, but won't block the addition of an option - but I think that we need to clearly document the caveat that it severely weakens the rule to the point that all it bans is string + nullish.

I think we should document alternatives and better patterns to use to help guide users towards better code because better code means you can have a stricter rule and a better codebase.

Agreed - I too am unhappy!

I think this is a common & deep enough documentation need that it makes sense to have a blog post explaining these things. And @bradzacher I think you're best positioned to write it 😄

(or, if you don't have the time, a scraping of all your posts on that issue & related issues+PRs might do...)

Affected URL(s)

https://typescript-eslint.io/blog/*