Incorrect default initial_connection_window_size/initial_stream_window_size value in doc

## Bug Report

The doc states the default size of initial_connection_window_size/initial_stream_window_size will be set to 65535.
[initial_stream_window_size](https://docs.rs/tonic/latest/tonic/transport/struct.Server.html#method.initial_stream_window_size)
[initial_connection_window_size](https://docs.rs/tonic/latest/tonic/transport/struct.Server.html#method.initial_connection_window_size)
[initial_stream_window_size](https://docs.rs/tonic/latest/tonic/transport/struct.Endpoint.html#method.initial_stream_window_size)
[initial_connection_window_size](https://docs.rs/tonic/latest/tonic/transport/struct.Endpoint.html#method.initial_connection_window_size)

The code in h2 shows the default size it sets is `1024 * 1024` for `Server` and `1024 * 1024*5`/`1024 * 1024*2` (unless adaptive_window was set to true)
https://github.com/hyperium/hyper/blob/81e25fa868c86e4ea81d5a96fdca497a4b1ab3c1/src/proto/h2/server.rs#L36
https://github.com/hyperium/hyper/blob/81e25fa868c86e4ea81d5a96fdca497a4b1ab3c1/src/proto/h2/client.rs#L37

### Version
tokio: 0.80
hyper: 0.14.20

### Platform

Darwin Kernel Version 21.6.0 and also ubuntu20