editSimilarityMap method
Returns a hashmap of terms to their editSimilarity with this.
Not case-sensitive.
Implementation
Map<String, double> editSimilarityMap(Iterable<String> terms) {
  final retVal = <String, double>{};
  for (var other in terms) {
    retVal[other] = editSimilarity(other);
  }
  return retVal;
}