Improve return value of resolveConfig, unwrap ResolvableTo

[RobinMalfait]

This PR improves the return type fo the resolveConfig a little bit.

In the config, a lot of values can be written in various forms (and most of it is optional). We also allow for dynamic "runtime" presets, so generating the perfect TypeScript types are almost impossible.

However, some of the parts in the config accept a function that resolves to type T, this improvement gets rid of the callback function and results in T directly (because calling resolveConfig should resolve this).

Fixes: #9929

[thecrypticace]

General approach looks good sans the change for handling theme.extend unwrapping and merging.

[justinh-kairos]

I'm still seeing this with tailwind 3.3.2:

Property 'colors' does not exist on type 'UnwrapResolvables<{ container: { center: true; padding: string; screens: { "2xl": string; }; }; extend: { fontFamily: { sans: [string, ...string[]]; display: [string, ...string[]]; }; colors: { input: string; ring: { DEFAULT: string; offset: string; }; ... 10 more ...; card: { ...; }; }; borderRadius: { ...; }; keyf...'.ts(2339)

[stefusilviu]

@justinh-kairos This seems to be solved in 3.4.1

[theocerutti]

No it still doesn't work:

const config = resolveConfig(tailwindConfig);

const mycolor = config.theme.colors.neutral['750']; // Element implicitly has an 'any' type because expression of type '750' can't be used to index type ...