New multi-router configuration system based on https://hackmd.io/G1KRDEX5T3qyfoBMkIrBew#Methods
- Added a new routing type: "custom"
- Added specific struct types for different Routers (instead of map[string]interface{})
- Added `Duration` config type, to make easier time string parsing
- Added config documentation.
- Use the latest go-delegated-routing library version with GET support.
- Added changelog notes for this feature.
It:
- closes#9157
- closes#9079
- closes#9186
Otherwise, we could end up with only DHT clients and never re-bootstrap.
I've left the default go-ipfs bootstrapping code in for now as it's technically
possible to disable the DHT entirely.
