Improve gRPC configuration max message size docs (#17838)

Author: JamesNK

aspnetcore/grpc/configuration.md

@@ -16,8 +16,8 @@ gRPC services are configured with `AddGrpc` in *Startup.cs*. The following table
 
 | Option | Default Value | Description |
 | ------ | ------------- | ----------- |
-| MaxSendMessageSize | `null` | The maximum message size in bytes that can be sent from the server. Attempting to send a message that exceeds the configured maximum message size results in an exception. |
-| MaxReceiveMessageSize | 4 MB | The maximum message size in bytes that can be received by the server. If the server receives a message that exceeds this limit, it throws an exception. Increasing this value allows the server to receive larger messages, but can negatively impact memory consumption. |
+| MaxSendMessageSize | `null` | The maximum message size in bytes that can be sent from the server. Attempting to send a message that exceeds the configured maximum message size results in an exception. When set to `null`, the message size is unlimited. |
+| MaxReceiveMessageSize | 4 MB | The maximum message size in bytes that can be received by the server. If the server receives a message that exceeds this limit, it throws an exception. Increasing this value allows the server to receive larger messages, but can negatively impact memory consumption. When set to `null`, the message size is unlimited. |
 | EnableDetailedErrors | `false` | If `true`, detailed exception messages are returned to clients when an exception is thrown in a service method. The default is `false`. Setting `EnableDetailedErrors` to `true` can leak sensitive information. |
 | CompressionProviders | gzip | A collection of compression providers used to compress and decompress messages. Custom compression providers can be created and added to the collection. The default configured providers support **gzip** compression. |
 | <span style="word-break:normal;word-wrap:normal">ResponseCompressionAlgorithm</span> | `null` | The compression algorithm used to compress messages sent from the server. The algorithm must match a compression provider in `CompressionProviders`. For the algorithm to compress a response, the client must indicate it supports the algorithm by sending it in the **grpc-accept-encoding** header. |
@@ -41,8 +41,8 @@ gRPC client configuration is set on `GrpcChannelOptions`. The following table de
 | HttpClient | New instance | The `HttpClient` used to make gRPC calls. A client can be set to configure a custom `HttpClientHandler`, or add additional handlers to the HTTP pipeline for gRPC calls. If no `HttpClient` is specified, then a new `HttpClient` instance is created for the channel. It will automatically be disposed. |
 | DisposeHttpClient | `false` | If `true`, and an `HttpClient` is specified, then the `HttpClient` instance will be disposed when the `GrpcChannel` is disposed. |
 | LoggerFactory | `null` | The `LoggerFactory` used by the client to log information about gRPC calls. A `LoggerFactory` instance can be resolved from dependency injection or created using `LoggerFactory.Create`. For examples of configuring logging, see <xref:grpc/diagnostics#grpc-client-logging>. |
-| MaxSendMessageSize | `null` | The maximum message size in bytes that can be sent from the client. Attempting to send a message that exceeds the configured maximum message size results in an exception. |
-| <span style="word-break:normal;word-wrap:normal">MaxReceiveMessageSize</span> | 4 MB | The maximum message size in bytes that can be received by the client. If the client receives a message that exceeds this limit, it throws an exception. Increasing this value allows the client to receive larger messages, but can negatively impact memory consumption. |
+| MaxSendMessageSize | `null` | The maximum message size in bytes that can be sent from the client. Attempting to send a message that exceeds the configured maximum message size results in an exception. When set to `null`, the message size is unlimited. |
+| <span style="word-break:normal;word-wrap:normal">MaxReceiveMessageSize</span> | 4 MB | The maximum message size in bytes that can be received by the client. If the client receives a message that exceeds this limit, it throws an exception. Increasing this value allows the client to receive larger messages, but can negatively impact memory consumption. When set to `null`, the message size is unlimited. |
 | Credentials | `null` | A `ChannelCredentials` instance. Credentials are used to add authentication metadata to gRPC calls. |
 | CompressionProviders | gzip | A collection of compression providers used to compress and decompress messages. Custom compression providers can be created and added to the collection. The default configured providers support **gzip** compression. |