noResults and VerticalResults README Updates

[creotutar]

Currently SDK supports

(1) For both UniversalResults and VerticalResults for legacy no results

    noResultsMessage: 'No Results',
    noResultsTryUniversalMessage: 'Try Universal',
    noResultsSuggestionsTitle: 'Try these',
    noResultsSuggestions: ['', '']

(2) For ANSWERS.init

  noResults: {
    // Optional, whether to display all results in the vertical when no results are found. Defaults to false, in which case only the no results card will be shown.
    displayAllResults: true
  },

(3) For VerticalResults

verticalPages: []