[Bugfix] Make KeyValuePair type allow string[] value

[p-runge]

Background

I wanted to update the max-h-screen class to use the dvh unit, but wanted it to still fallback to vh for old browser support.

Tailwind allows doing that using an array of strings, so this:

import type { Config } from "tailwindcss";

export default {
  // ...
  theme: {
    extend: {
      maxHeight: {
        screen: ["100vh", "100dvh"],
      },
    },
  },
} satisfies Config;

results in this:

.max-h-screen {
  max-height: 100vh;
  max-height: 100dvh;
}

The Problem

The problem is, the types don't allow it. So actually using the satisfies Config on the config object errors saying:
Type 'string[]' is not assignable to type 'string'.ts(2322)

So changing the KeyValuePair type in the config.d.ts from

type KeyValuePair<K extends keyof any = string, V = string> = Record<K, V>

to

type KeyValuePair<K extends keyof any = string, V = string | string[]> = Record<K, V>

should do the trick.

If I get the "go", I'd like to create a PR for this.