Specify recommended GossipSub parameters

[jm-clius]

Problem

libp2p PubSub, FloodSub and GossipSub define a long list of tweakable parameters that control the underlying behaviour of each protocol (for example, here and here).

Although most client implementations use the Reasonable Default, as specified, for all parameters, it is likely that some of these parameters will be tweaked for Waku v2. For example, the nim-waku client already sets the PruneBackoff to 30 seconds, rather than the default 1 minute.

It is important for the stability of a Waku v2 network that all participating clients agree on these parameters. We should therefore clearly specify suggested tweaks and recommend that all Waku v2 client implementations follow the scheme.

cc @siphiuel @D4nte @richard-ramos

Acceptance Criteria

• [ ] A list of tweakable GossipSub parameters with their recommended values for Waku v2.