fix(node-fetch): Change incorrect [string] to string

[wjhsf]

The current definition for Headers has values(): IterableIterator<[string]>. The implementation is actually values(): IterableIterator<string> (spec compliant).

• Use a meaningful title for the pull request. Include the name of the package modified.
• Test the change in your own code. (Compile and run.)
• Add or edit tests to reflect the change.
• Follow the advice from the readme.
• Avoid common mistakes.
• Run npm test <package to test>.

If changing an existing definition:

• Provide a URL to documentation or source code which provides context for the suggested changes: https://www.npmjs.com/package/node-fetch#class-headers

[typescript-bot]

@wjhsf Thank you for submitting this PR! I see this is your first time submitting to DefinitelyTyped 👋 — I'm the local bot who will help you through the process of getting things through.

This is a live comment which I will keep updated.

1 package in this PR

• node-fetch — on npm, on unpkg
  • owner-approval: @AndrewLeedham, @nikcorg, @kyranet, @OmgImAlexis

Code Reviews

Because this is a widely-used package, a DT maintainer will need to review it before it can be merged.

You can test the changes of this PR in the Playground.

Status

• ✅ No merge conflicts
• ✅ Continuous integration tests have passed
• 🕐 Most recent commit is approved by a DT maintainer

Once every item on this list is checked, I'll ask you for permission to merge and publish the changes.

---

Diagnostic Information: What the bot saw about this PR

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[typescript-bot]

🔔 @torstenwerner @nikcorg @vinaybedre @kyranet @AndrewLeedham @JasonLi914 @southpolesteve @ExE-Boss @alexandrusavin @OmgImAlexis @kbkk — please review this PR in the next few days. Be sure to explicitly select Approve or Request Changes in the GitHub UI so I know what's going on.

[OmgImAlexis]

LGTM

[typescript-bot]

I just published @types/node-fetch@2.5.12 to npm.