feat(docs) Add import style guide

[yewman]

Implement style guide roughly defined here #184

Note:

Consideration of using local imports within modules so that lib files expose only the public interface of a module
Could use the following approach for imports (src/gossip/service.zig)

const sig = https://github.com/import("../lib.zig");
const lib = struct {
const table = https://github.com/import("table.zig");
const active_set = https://github.com/import("active_set.zig");
};

const SocketAddr = sig.net.SocketAddr;
const ServiceManager = sig.utils.service_manager.ServiceManager;
const GossipTable = lib.table.GossipTable;
const HashTimeQueue = lib.table.HashTimeQueue;
const AutoArrayHashSet = lib.table.AutoArrayHashSet;

[0xNineteen]

nice