Enable delegated routing

Delegated peer and content routing is supported by the latest js-ipfs (https://github.com/ipfs/js-ipfs/issues/2155) + https://github.com/libp2p/js-libp2p-delegated-content-routing / https://github.com/libp2p/js-libp2p-delegated-peer-routing

Enabling it with `*.delegate.ipfs.io` should improve this sharing app:

- On the sender end `provide` call executes preload on delegate node ([libp2p-delegated-content-routing/index.js#L90-L92](https://github.com/libp2p/js-libp2p-delegated-content-routing/blob/master/src/index.js#L90-L92))
- On the receiver end, delegated DHT provides alternative to ws-starwebrtc-star signaling