Add support for twitter label meta

[pveyes]

Describe the feature you'd like to request

Add new twitter meta fields to support custom label. Slack (not sure if other services do) reads twitter:label and twitter:data meta

<meta name="twitter:label1" content="Written by" />
<meta name="twitter:data1" content="Fatih Kalifa" />
<meta name="twitter:label2" content="reading Time" />
<meta name="twitter:data2" content="12 mins read" />

This will be rendered like this

Other examples: https://twitter.com/levelsio/status/828892835172671489?lang=en

Describe the solution you'd like

Provide optional twitter:labels array in Metadata type

function generateMetadata() {
  return {
    twitter: {
      labels: [
        { key: "Written by", value: "Fatih Kalifa" },
        { key: "reading Time", value: "12 mins read" },
      ]
    }
  }
}

Describe alternatives you've considered

Tried rendering the meta tag in page.js, but it didn't work

[ciruz]

You can define other metatags as well, like so:

export const metadata = {
  title: "Home",
  description: "Welcome to Next.js",
  other: {
    ["twitter:label1"]: "written by",
    ["twitter:data1"]: "foobar",
  },
};

HTML result:

So it's already possible.

[huozhi]

Yeah, should use metadata.other should be the one to use, twitter:card and twitter:label are not official properties defined in https://developer.twitter.com/en/docs/twitter-for-websites/cards/overview/markup.