Document "Advertise security protocol in multiaddr"

[p-shahi]

A proposal to include the security protocol (TLS or Noise) in the multiaddr is being proposed. This is a performance optimization to reduce time spent in protocol negotiation.
go-libp2p is planning to implement this in Q1 2023 and rust-libp2p in Q2 2023.

• The spec draft for this change is here: addressing: Specify security protocols in multiaddr specs#353

Done Criteria

• Updates that describe the change to multiaddr format
• Describes how the security protocol to be used is determined by multiaddr
• Describe the optimization (how 1 RTT is saved)
• Decide where to add this section: under a new Advanced Concepts section, under general connection establishment section? how to reference in docs for secure channels (TLS and Noise). Relates to add: fundamentals doc on connections #202 and Populate secure communication section: Noise & TLS #19

Why Important

We need to document and highlight the performance optimizations libp2p has specified and implemented.