Fixed couple of unfinished properties

src/Discord.Net.Rest/API/Common/ApplicationCommand.cs

@@ -12,6 +12,6 @@ namespace Discord.API
         public ulong ApplicationId { get; set; }
         public string Name { get; set; }
         public string Description { get; set; }
-        public IEnumerable<ApplicationCommand>
+        public ApplicationCommand[] Options { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/ApplicationCommandInteractionData.cs

@@ -16,6 +16,6 @@ namespace Discord.API
         public string Name { get; set; }
 
         [JsonProperty("options")]
-        public Optional<IEnumerable<ApplicationCommandInteractionDataOption>>
+        public Optional<ApplicationCommandInteractionDataOption[]> Options { get; set; } 
     }
 }