add tvu port binding info to docs

[alexpyattaev]

Summary of Changes

• Documenting how we get multiple bound TVU sockets published via gossip.

[alexpyattaev]

@gregcusack do you like this?

[gregcusack]

thank you for putting this together! just a few thoughts. biggest thing is that we should probably differentiate TVU quic and udp sockets. And then somewhere add that TPU is setup somewhat similarly. Although TPU also uses bind_more_with_config which I believe just enables more connections and ability to distribute load better.

[gregcusack]

so we have both UDP and QUIC ports for TVU. Probably makes sense to differentiate these two somewhere. UDP multibind with reuseport works on OS level. For quic tvu, we only bind to one socket. and the multiplexing is done at the protocol level.

[alexpyattaev]

done

[gregcusack]

external ip/port for TVU/TPU.

would maybe leave out TPU inline here. Maybe we can add something right after or even at the top saying TPU runs on similar port management logic

[alexpyattaev]

added note about TPU

[gregcusack]

Suggested change

	```rust
	const SOCKET_TAG_TVU: u8 = 10; // For UDP
	const SOCKET_TAG_TVU_QUIC: u8 = 11; // For QUIC
	```rust
	const SOCKET_TAG_TVU: u8 = 10; // For UDP
	const SOCKET_TAG_TVU_QUIC: u8 = 11; // For QUIC

^ note the missing code block closing "```"

[gregcusack]

ok this formatted weird. but basically, we're missing a ``` at the end of this block, so formatting is weird