Feature(Docs): Another way for preloading languages to discuss

[thekhegay]

First way: Prefetch the User Language
Second way: Preload Languages

New way:

import { APP_INITIALIZER, Provider } from '@angular/core';
import { forkJoin, lastValueFrom } from 'rxjs';

import { TranslocoService } from '@ngneat/transloco';

function translocoPreloadFactory(translocoService: TranslocoService) {
  return () => {
    const call = ['en', 'es'].reduce(
      (o, lang) => ({
        ...o,
        [lang]: translocoService.load(lang),
      }),
      {}
    );
    return lastValueFrom(forkJoin(call));
  };
}

export const providePreloadTransloco: Provider = {
  provide: APP_INITIALIZER,
  useFactory: translocoPreloadFactory,
  deps: [TranslocoService],
  multi: true,
};