Add selector option to Theme config

[mertsincan]

The darkModeSelector can be deprecated. A possible new approach could be:

Types;

interface SelectorOptions {
    /**
     * @default ':root'
     */
    default?: string;
    /**
     * @default ':root' | '@media (prefers-color-scheme: light)'  | '@media (prefers-color-scheme: light) { :root { [CSS] } }'
     */
    light?: 'none' | string | boolean;
    /**
     * @default '@media (prefers-color-scheme: dark)' | '@media (prefers-color-scheme: dark) { :root { [CSS] } }'
     */
    dark?: 'none' | string | boolean;
}

/**
 * @default 'system'
 */
declare type Selector = 'system' | 'none' | SelectorOptions;

Usages;

options: {
    selector: 'system' // shorthand to set default value
    ...
}

options: {
    selector: 'none' // { default: ':root', light: 'none', dark: 'none' }
    ...
}

options: {
    selector: {
        light: '.lightClass',
        dark: '.darkClass'
    },
    ...
}

options: {
    selector: {
        light: '@scope (.lightClass)', // OR '@scope (.lightClass){ :scope { [CSS] } }'
        dark: '@scope (.darkClass)' // OR '@scope (.darkClass){ :scope { [CSS] } }'
    } ,
    ...
}