Add documentation for fuzziness

See elastic/elasticsearch#18322

Author: russcam

src/Nest/CommonOptions/Fuzziness/Fuzziness.cs

@@ -5,20 +5,15 @@ public class Fuzziness : IFuzziness
 		private bool _auto;
 		private int? _editDistance;
 		private double? _ratio;
-		bool IFuzziness.Auto { get { return this._auto; } }
-		int? IFuzziness.EditDistance { get { return this._editDistance; } }
-		double? IFuzziness.Ratio { get { return this._ratio; } }
 
-		public static Fuzziness Auto { get { return new Fuzziness() { _auto = true }; } }
+		bool IFuzziness.Auto => this._auto;
+		int? IFuzziness.EditDistance => this._editDistance;
+		double? IFuzziness.Ratio => this._ratio;
 
-		public static Fuzziness EditDistance(int distance)
-		{
-			return new Fuzziness() { _editDistance = distance };
-		}
+		public static Fuzziness Auto => new Fuzziness { _auto = true };
 
-		public static Fuzziness Ratio(double ratio)
-		{
-			return new Fuzziness() { _ratio = ratio };
-		}
+		public static Fuzziness EditDistance(int distance) => new Fuzziness { _editDistance = distance };
+
+		public static Fuzziness Ratio(double ratio) => new Fuzziness { _ratio = ratio };
 	}
-}
+}

src/Nest/QueryDsl/FullText/MultiMatch/MultiMatchQuery.cs

@@ -8,54 +8,59 @@ namespace Nest
 	[JsonConverter(typeof(ReadAsTypeJsonConverter<MultiMatchQueryDescriptor<object>>))]
 	public interface IMultiMatchQuery : IQuery
 	{
-		[JsonProperty(PropertyName = "type")]
-		[JsonConverter(typeof(StringEnumConverter))]
+		[JsonProperty("type")]
 		TextQueryType? Type { get; set; }
 
-		[JsonProperty(PropertyName = "query")]
+		[JsonProperty("query")]
 		string Query { get; set; }
 
-		[JsonProperty(PropertyName = "analyzer")]
+		[JsonProperty("analyzer")]
 		string Analyzer { get; set; }
 
-		[JsonProperty(PropertyName = "fuzzy_rewrite")]
-		[JsonConverter(typeof(StringEnumConverter))]
+		[JsonProperty("fuzzy_rewrite")]
 		RewriteMultiTerm? FuzzyRewrite { get; set; }
 
-		[JsonProperty(PropertyName = "fuzziness")]
+		/// <summary>
+		/// Allows fuzzy matching based on the type of field being queried.
+		/// Cannot be used with the
+		/// <see cref="TextQueryType.CrossFields"/>,
+		/// <see cref="TextQueryType.Phrase"/> or
+		/// <see cref="TextQueryType.PhrasePrefix"/> types.
+		/// </summary>
+		[JsonProperty("fuzziness")]
 		Fuzziness Fuzziness { get; set; }
 
-		[JsonProperty(PropertyName = "cutoff_frequency")]
+		[JsonProperty("cutoff_frequency")]
 		double? CutoffFrequency { get; set; }
 
-		[JsonProperty(PropertyName = "prefix_length")]
+		[JsonProperty("prefix_length")]
 		int? PrefixLength { get; set; }
 
-		[JsonProperty(PropertyName = "max_expansions")]
+		[JsonProperty("max_expansions")]
 		int? MaxExpansions { get; set; }
 
-		[JsonProperty(PropertyName = "slop")]
+		[JsonProperty("slop")]
 		int? Slop { get; set; }
 
-		[JsonProperty(PropertyName = "lenient")]
+		[JsonProperty("lenient")]
 		bool? Lenient { get; set; }
 
-		[JsonProperty(PropertyName = "use_dis_max")]
+		[JsonProperty("use_dis_max")]
 		bool? UseDisMax { get; set; }
 
-		[JsonProperty(PropertyName = "tie_breaker")]
+		[JsonProperty("tie_breaker")]
 		double? TieBreaker { get; set; }
 
-		[JsonProperty(PropertyName = "minimum_should_match")]
+		[JsonProperty("minimum_should_match")]
 		MinimumShouldMatch MinimumShouldMatch { get; set; }
 
-		[JsonProperty(PropertyName = "operator")]
+		[JsonProperty("operator")]
 		Operator? Operator { get; set; }
 
-		[JsonProperty(PropertyName = "fields")]
+		[JsonProperty("fields")]
 		Fields Fields { get; set; }
 
-		[JsonProperty(PropertyName = "zero_terms_query")]
+		[JsonProperty("zero_terms_query")]
 		ZeroTermsQuery? ZeroTermsQuery { get; set; }
 	}
 
@@ -66,6 +71,14 @@ public class MultiMatchQuery : QueryBase, IMultiMatchQuery
 		public string Query { get; set; }
 		public string Analyzer { get; set; }
 		public RewriteMultiTerm? FuzzyRewrite { get; set; }
+
+		/// <summary>
+		/// Allows fuzzy matching based on the type of field being queried.
+		/// Cannot be used with the
+		/// <see cref="TextQueryType.CrossFields"/>,
+		/// <see cref="TextQueryType.Phrase"/> or
+		/// <see cref="TextQueryType.PhrasePrefix"/> types.
+		/// </summary>
 		public Fuzziness Fuzziness { get; set; }
 		public double? CutoffFrequency { get; set; }
 		public int? PrefixLength { get; set; }
@@ -116,6 +129,13 @@ public MultiMatchQueryDescriptor<T> Fields(Func<FieldsDescriptor<T>, IPromise<Fi
 
 		public MultiMatchQueryDescriptor<T> Analyzer(string analyzer) => Assign(a => a.Analyzer = analyzer);
 
+		/// <summary>
+		/// Allows fuzzy matching based on the type of field being queried.
+		/// Cannot be used with the
+		/// <see cref="TextQueryType.CrossFields"/>,
+		/// <see cref="TextQueryType.Phrase"/> or
+		/// <see cref="TextQueryType.PhrasePrefix"/> types.
+		/// </summary>
 		public MultiMatchQueryDescriptor<T> Fuzziness(Fuzziness fuzziness) => Assign(a => a.Fuzziness = fuzziness);
 
 		public MultiMatchQueryDescriptor<T> CutoffFrequency(double cutoffFrequency)