Max/Min length fields for ApplicationCommandOption (#2379)

* implement max/min length fields for ApplicationCommandOption

* fix badly formed xml comments

src/Discord.Net.Interactions/Info/Parameters/SlashCommandParameterInfo.cs

@@ -38,6 +38,16 @@ namespace Discord.Interactions
         /// </summary>
         public double? MaxValue { get; }
 
+        /// <summary>
+        ///     Gets the minimum length allowed for a string type parameter.
+        /// </summary>
+        public int? MinLength { get; }
+
+        /// <summary>
+        ///     Gets the maximum length allowed for a string type parameter.
+        /// </summary>
+        public int? MaxLength { get; }
+
         /// <summary>
         ///     Gets the <see cref="TypeConverter{T}"/> that will be used to convert the incoming <see cref="Discord.WebSocket.SocketSlashCommandDataOption"/> into
         ///     <see cref="CommandParameterInfo.ParameterType"/>.
@@ -86,6 +96,8 @@ namespace Discord.Interactions
             Description = builder.Description;
             MaxValue = builder.MaxValue;
             MinValue = builder.MinValue;
+            MinLength = builder.MinLength;
+            MaxLength = builder.MaxLength;
             IsComplexParameter = builder.IsComplexParameter;
             IsAutocomplete = builder.Autocomplete;
             Choices = builder.Choices.ToImmutableArray();