[CONTENT REQUEST] document peer ids more thoroughly

I couldn't find documentation on peer ids, aside from a brief glossary entry which linked to the DHTs page. That page doesn't talk about the nature of peer ids themselves, just how they're used in the DHT.

At minimum, it should link to the libp2p documentation on the topic: https://docs.libp2p.io/concepts/fundamentals/peers/

A common topic I get questions about is peer id stability / life-cycle.

Here's a list of topics to cover off the top of my head:

- how do the various mature implementations create peer ids? and when?
- how are they managed, and where?
- what are the conditions under which a peer id would change?
- as a developer, what are some reasons i might want to change my peer id?
- what are the repercussions of changing a peer id?
- what are some common patterns/challenges in ipfs applications which use peer ids as identity?