static features() {
    return { relative: hasRelative(), localeWeek: hasLocaleWeekInfo() };
  }
Return the set of available features in this environment.
Some features of Luxon are not available in all environments. For example, on older browsers, relative time formatting support is not available. Use this function to figure out if that's the case.
Keys:
* `relative`: whether this environment supports relative time formatting
* `localeWeek`: whether this environment supports different weekdays for the start of the week based on the locale
@example Info.features() //=> { relative: false, localeWeek: true }
@return {Object}