Content-Type, and potentially other headers, for the different types of feeds

[Svish]

Is your feature request related to a problem? Please describe. Writing routes in Next.js which will return feeds generated by this library, but unsure what headers to send with the response.

import { NextResponse } from 'next/server'
import { createFeed } from '@/feed'

export async function GET() {
  const feed = createFeed()

  return new NextResponse(feed.rss2(), {
    headers: {
      'content-type': 'text/xml; charset=utf-8', // Hopefully correct ... ?
    },
  })
}

Describe the solution you'd like The current .rss2(), .atom1() and .json1() functions just return a string. Would be great if there were alternatives to those which simply returned standard Response objects with the rendered feed as the body and appropriate headers already setup.

import { createFeed } from '@/feed'

export async function GET() {
  return createFeed().toResponse('rss2')
}

Describe alternatives you've considered Can of course just do it manually, like everyone else using this are probably doing, but I'm guessing that serving the rendered string from a server is probably one of the most common things to do with this library, so would be great if this could be handled right out of the box. 🧙‍♂️